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As filed with the United States Securities and Exchange Commission on November 10, 2022

Registration No. 333-    

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-4

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

HH&L Acquisition Co.*

(Exact Name of Registrant as Specified in its Charter)

Cayman Islands
(State or other jurisdiction of
incorporation or organization)

6770
(Primary Standard Industrial
Classification Code Number)

N/A
(I.R.S. Employer
Identification Number)

Suite 2001-2002, 20/F, York House

The Landmark, 15 Queen’s Road Central

Central, Hong Kong

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Puglisi & Associates

850 Library Avenue, Suite 204

Newark, Delaware 19711

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Joel L. Rubinstein
White & Case LLP
1221 Avenue of the Americas
New York, New York 10020
(212) 819-8200

Jessica Zhou
White & Case
16th Floor, York House
The Landmark, 15 Queen’s Road Central
Central, Hong Kong
(852) 2822 8725

Mitchell S. Nussbaum, Esq.

Loeb & Loeb LLP

345 Park Avenue
New York, NY 10154
(212) 407-4000

Janeane R. Ferrari, Esq.

Loeb & Loeb LLP
345 Park Avenue

New York, NY 10154
(212) 407-4000

Approximate date of commencement of proposed sale of the securities to the public: As soon as practicable after this Registration Statement becomes effective and all other conditions to the business combination described in the enclosed proxy statement / prospectus have been satisfied or waived.

If the securities being registered on this Form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box:

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer

Accelerated filer

Non-accelerated filer

Smaller reporting company

Emerging growth company

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

Exchange Act Rule 13e-4(i)  (Cross-Border Issuer Tender Offer)  ☐

Exchange Act Rule 14d-1(d) (Cross-Border Third-Party Tender Offer)  ☐

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act or until the registration statement shall become effective on such date as the SEC, acting pursuant to said Section 8(a), may determine.

*

Immediately prior to the consummation of the business combination described in the enclosed proxy statement/prospectus, the Registrant intends to effect a deregistration under section 206 of the Cayman Islands Companies Act and a domestication under Section 388 of the Delaware General Corporation Law, pursuant to which HH&L’s jurisdiction of incorporation will be changed from the Cayman Islands to the State of Delaware (the “HH&L Domestication”). All securities being registered will be issued by the continuing entity following the HH&L Domestication, which will be renamed “DiaCarta, Inc.” upon the consummation of the HH&L Domestication. As used herein, “Domesticated HH&L” refers to the Registrant after giving effect to the HH&L Domestication but before the consummation of the business combination, while “DiaCarta PubCo” refers to the Registrant after giving effect to the HH&L Domestication and the business combination.

The information in this preliminary proxy statement / prospectus is not complete and may be changed. The registrant may not sell the securities described in this preliminary proxy statement / prospectus until the registration statement filed with the Securities and Exchange Commission is declared effective. This preliminary proxy statement / prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

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SUBJECT TO COMPLETION, DATED NOVEMBER 10, 2022

PRELIMINARY PROXY STATEMENT FOR

EXTRAORDINARY GENERAL MEETING OF

HH&L ACQUISITION CO.

(A CAYMAN ISLANDS EXEMPTED COMPANY)

PROSPECTUS FOR

87,400,000 SHARES OF COMMON STOCK AND

20,700,000 REDEEMABLE WARRANTS

OF

HH&L ACQUISITION CO.

(TO BE RENAMED “DIACARTA, INC.”

FOLLOWING ITS DOMESTICATION

AS A CORPORATION INCORPORATED IN THE STATE OF DELAWARE,

IN CONNECTION WITH THE BUSINESS COMBINATION DESCRIBED HEREIN)

The board of directors of HH&L Acquisition Co., a Cayman Islands exempted company incorporated with limited liability (“HH&L” and, after the HH&L Domestication as described below, “Domesticated HH&L” and, following the Merger described below, “DiaCarta PubCo”), has unanimously approved (1) the domestication of HH&L as a Delaware corporation (which will be renamed “DiaCarta, Inc.” prior to the consummation of the Business Combination as described below) (the “HH&L Domestication”); (2) the merger of Diamond Merger Sub Inc., a Delaware corporation and direct wholly owned subsidiary of HH&L (“Merger Sub”), with and into DiaCarta, Ltd., a Cayman Islands exempted company incorporated with limited liability (“DiaCarta” and, after the DiaCarta Domestication as described below, “Domesticated DiaCarta”), which will domesticate (such domestication, the “DiaCarta Domestication”) as a Delaware corporation prior to the merger (the “Merger” and, together with the HH&L Domestication, the “Business Combination”), with Domesticated DiaCarta surviving the Merger as a wholly owned subsidiary of DiaCarta PubCo, pursuant to the terms of the Business Combination Agreement, dated as of October 14, 2022, by and among HH&L, Merger Sub and DiaCarta, attached to this proxy statement / prospectus as Annex A (as may be amended from time to time, the “Merger Agreement”), as more fully described elsewhere in this proxy statement / prospectus; and (3) the other transactions contemplated by the Merger Agreement and documents related thereto. In connection with the Business Combination, HH&L will change its name to “DiaCarta, Inc.” HH&L and DiaCarta PubCo, following the HH&L Domestication, are both referred to herein as the Company.

In connection with the HH&L Domestication, (1) each of the then issued and outstanding 10,350,000 Class B ordinary shares, par value $0.0001 per share, of HH&L (the “HH&L Class B ordinary shares”) shall, immediately prior to the HH&L Domestication, convert automatically into a HH&L Class A ordinary share (as defined below) (subject to adjustment of the conversion ratio as provided by the terms of the Cayman Constitutional Documents (as defined below), as applicable) in accordance with and pursuant to the approvals to be obtained from the shareholders of HH&L, including the approval of the requisite majority of the holders of HH&L Class B ordinary shares, (2) immediately following the conversion described in clause (1), each of the then issued and outstanding 51,750,000 Class A ordinary shares, par value $0.0001 per share, of HH&L (the “HH&L Class A ordinary shares”) (including those Class A ordinary shares resulting from the conversion described in clause (1) and those Class A ordinary shares underlying the HH&L units (as defined below)), shall convert automatically, on a one-for-one basis, into a share of common stock, par value $0.0001 per share, of DiaCarta PubCo (the “DiaCarta PubCo common stock”), (3) each of the then issued and outstanding 30,980,000 redeemable warrants of HH&L (the “HH&L warrants”) (including those warrants underlying the HH&L units) will convert automatically into a redeemable warrant to acquire one share of DiaCarta PubCo common stock (the “DiaCarta PubCo warrants”) pursuant to the Warrant Agreement, dated February 5, 2021 (the “Warrant Agreement”), between HH&L and Continental Stock Transfer & Trust Company (“Continental”), as warrant agent, and (4) each of the then issued and outstanding units of HH&L (the “HH&L units”) that have not been previously separated into the underlying HH&L Class A ordinary shares and underlying HH&L warrants upon the request of the holder thereof, will convert into a unit of DiaCarta PubCo (the “DiaCarta PubCo units”), with each DiaCarta PubCo unit representing one share of DiaCarta PubCo common stock and one-half (1/2) of one DiaCarta PubCo warrant. Upon the closing of the Business Combination, immediately prior to the effective time of the Merger, each issued and outstanding DiaCarta PubCo unit immediately prior to the effective time will be automatically separated and the holder thereof shall be deemed to hold one share of DiaCarta PubCo common stock and one-half (1/2) of one DiaCarta PubCo warrant.

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No fractional DiaCarta PubCo warrants will be issued upon separation of the DiaCarta PubCo units.  Accordingly, this proxy statement / prospectus covers the 41,400,000 shares of DiaCarta PubCo common stock and 20,700,000 DiaCarta PubCo warrants to be issued in the HH&L Domestication in respect of the HH&L Class A ordinary shares and HH&L warrants which were initially included in the HH&L units sold in HH&L’s initial public offering.

In connection with the DiaCarta Domestication, (1) each of the then issued and outstanding 28,489,472 ordinary shares, par value $0.001 per share, of DiaCarta (the “DiaCarta ordinary shares”) will convert, on a one-for-one basis, into a share of common stock, par value $0.001 per share, of Domesticated DiaCarta (the “Domesticated DiaCarta common stock”); (2) each of the then issued and outstanding 7,543,978 Series A Preference Shares, par value $0.001 per share, of DiaCarta (the “DiaCarta Series A Preference Shares”) will convert, on a one-for-one basis, into a share of Domesticated DiaCarta common stock; (3) each of the then issued and outstanding 12,183,137 Series B Preference Shares, par value $0.001 per share, of DiaCarta (the “DiaCarta Series B Preference Shares”) will convert, on a one a one-for-one basis, into a share of Domesticated DiaCarta common stock; (4) each of the then outstanding options to purchase DiaCarta ordinary shares (the “DiaCarta Options”) will convert into an option to acquire, on a one-for-one basis and subject to substantially the same terms and conditions as were applicable under such DiaCarta Options immediately before the DiaCarta Domestication, shares of Domesticated DiaCarta common stock (the “Domesticated DiaCarta options”); and (5) each of the then issued and outstanding warrants of DiaCarta to purchase the DiaCarta Series B Preference Shares (the “DiaCarta warrants”) will convert into a warrant to acquire, on a one-for-one basis and subject to substantially the same terms and conditions as were applicable under such DiaCarta warrants immediately before the DiaCarta Domestication, shares of Domesticated DiaCarta common stock (the “Domesticated DiaCarta warrants”).

As a result of and upon the closing of the Business Combination, among other things, each share of Domesticated DiaCarta common stock (after giving effect to the DiaCarta Domestication) issued and outstanding as of immediately prior to the effective time of the Merger will be cancelled in exchange for the right to receive a number of shares of DiaCarta PubCo common stock equal to the Exchange Ratio. “Exchange Ratio” means the quotient obtained by dividing (a) the number of shares (at a deemed value of $10.00 per share) constituting a fully-diluted pre-transaction equity value of DiaCarta of $460 million, by (b) the aggregate number of shares of Domesticated DiaCarta common stock that are (i) issued and outstanding immediately prior to the effective time, and (ii) issuable upon, or subject to, the exercise of Domesticated DiaCarta options or Domesticated DiaCarta warrants (whether or not then vested or exercisable), in each case, that are outstanding immediately prior to the effective time.

At the effective time of the Merger, (1) each Domesticated DiaCarta option outstanding immediately prior to the effective time will be converted into an option to acquire, upon substantially the same terms and conditions as are in effect with respect to such option immediately prior to the effective time, the number of shares of DiaCarta PubCo common stock, determined by multiplying (A) the number of shares of Domesticated DiaCarta common stock subject to such Domesticated DiaCarta option as of immediately prior to the effective time, by (B) the Exchange Ratio, at an exercise price per share of DiaCarta PubCo common stock equal to (i) the exercise price per share of Domesticated DiaCarta common stock of such Domesticated DiaCarta option in effect immediately prior to the effective time, divided by (ii) the Exchange Ratio (each, a “DiaCarta PubCo Option”); and (2) each Domesticated DiaCarta warrant issued and outstanding immediately prior to the effective time will be converted into a warrant to acquire, subject to substantially the same terms and conditions as were applicable under such DiaCarta warrant, the number of shares of DiaCarta PubCo common stock, determined by multiplying (A) the number of shares of Domesticated DiaCarta common stock subject to such Domesticated DiaCarta warrant immediately prior to the effective time, by (B) the Exchange Ratio, at an exercise price per share of DiaCarta PubCo common stock equal to (i) the exercise price per share of Domesticated DiaCarta common stock of such Domesticated DiaCarta warrant divided by (ii) the Exchange Ratio (each, a “Converted DiaCarta PubCo Warrant”). At the effective time of the Merger, DiaCarta PubCo will assume all obligations of Domesticated DiaCarta with respect to the Domesticated DiaCarta options and Domesticated DiaCarta warrants, as converted.

Accordingly, this proxy statement / prospectus also covers 43,368,218 shares of DiaCarta PubCo common stock to be issued to the holders of shares of Domesticated DiaCarta common stock in connection with the Merger. See “BCA Proposal — Consideration — Treatment of DiaCarta Options and DiaCarta Warrants.”

The HH&L units, HH&L Class A ordinary shares and public warrants are currently listed on the New York Stock Exchange (the “NYSE”) under the symbols “HHLA.U,” “HHLA” and “HHLA WS,” respectively. HH&L will apply for listing, to be effective at the time of the Business Combination, of DiaCarta PubCo common stock and DiaCarta PubCo warrants on the NYSE under the proposed symbols “       ” and “       ”, respectively. DiaCarta PubCo will not have units traded.

DiaCarta’s principal operations are conducted in the United States with significant additional operations in the PRC. The PRC business is conducted as a separate, stand-alone business from DiaCarta’s non-PRC operations. All PRC manufacturing is done inside

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the PRC, relying exclusively upon PRC suppliers and all such manufactured products are sold within the PRC. All sales, marketing and administration for PRC operations is performed inside the PRC by employees or subcontractors of DiaCarta’s PRC subsidiaries. Similarly, none of DiaCarta’s operations outside the PRC are involved in serving PRC customers, supporting PRC operations or manufacturing for the PRC market. Further, DiaCarta does not have any variable interest entities structure in place. We believe that this structure benefits DiaCarta by isolating the risks associated with doing business in the PRC. Nevertheless, DiaCarta derives substantial revenue from PRC operations, and faces various legal and operational risks and uncertainties relating to its operations in China. See “Risk Factors — Risks Related to DiaCarta’s Operations Outside the United States and in the PRC.

HH&L is a blank check company incorporated on September 4, 2020 as a Cayman Islands exempted company incorporated with limited liability with its office located in Hong Kong for the purpose of effecting a merger, share exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses, and following the HH&L Domestication, will be renamed as DiaCarta, Inc. and domesticated as a corporation incorporated in the State of Delaware. See “Risk Factors — Risks if the Domestication and the Business Combination are not consummated — Because HH&L is incorporated under the laws of the Cayman Islands, in the event the Business Combination is not completed, you may face difficulties in protecting your interests, and your ability to protect your rights through the U.S. federal courts may be limited.”

HH&L will hold an extraordinary general meeting (the “extraordinary general meeting”) to consider matters relating to the Business Combination at             , Eastern Time, on                 . For the purposes of Cayman Islands law and the second amended and restated memorandum and articles of association of HH&L (as may be amended from time to time, the “Cayman Constitutional Documents”), the physical location of the extraordinary general meeting shall be at the offices of White & Case LLP at 1221 Avenue of the Americas, New York, New York 10020, or you or your proxyholder will be able to attend and vote at the extraordinary general meeting online by visiting https://www.cstproxy.com/hhlacquisition/2022 and using a control number assigned by Continental Stock Transfer & Trust Company. To register and receive access to the extraordinary general meeting, registered shareholders and beneficial shareholders (those holding shares through a stock brokerage account or by a bank or other holder of record) will need to follow the instructions applicable to them provided in the accompanying proxy statement / prospectus.

If you have any questions or need assistance voting your shares of common stock, please contact Morrow Sodali, our proxy solicitor, by calling (800) 662-5200, or banks and brokers can call at (203) 658-9400, or by emailing HHLA.info@investor.morrowsodali.com. The notice of the extraordinary general meeting and the proxy statement / prospectus relating to the Business Combination will be available at https://www.cstproxy.com/hhlacquisition/2022.

This proxy statement / prospectus provides shareholders of HH&L with detailed information about the proposed Business Combination and other matters to be considered at the extraordinary general meeting of HH&L. We encourage you to read this entire document, including the Annexes and other documents referred to herein, carefully and in their entirety. You should also carefully consider the risk factors described under the heading “Risk Factors” beginning on page 61 of this proxy statement / prospectus.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES REGULATORY AGENCY HAS APPROVED OR DISAPPROVED THE TRANSACTIONS DESCRIBED IN THIS PROXY STATEMENT / PROSPECTUS, PASSED UPON THE MERITS OR FAIRNESS OF THE BUSINESS COMBINATION OR RELATED TRANSACTIONS OR PASSED UPON THE ADEQUACY OR ACCURACY OF THE DISCLOSURE IN THIS PROXY STATEMENT / PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY CONSTITUTES A CRIMINAL OFFENSE.

This proxy statement / prospectus is dated                , and

is first being mailed to HH&L’s shareholders on or about                .

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HH&L Acquisition Co.

A Cayman Islands Exempted Company

(Company Incorporation Number 365837)

P.O. Box 309, Ugland House

Grand Cayman

KY1-1104

Cayman Islands

Dear HH&L Acquisition Co. Shareholders:

You are cordially invited to attend the extraordinary general meeting (the “extraordinary general meeting”) of HH&L Acquisition Co., a Cayman Islands exempted company incorporated with limited liability (“HH&L” and, after the HH&L Domestication, as described below, “DiaCarta PubCo”), at                 , Eastern Time, on                 . For the purposes of Cayman Islands law and the second amended and restated memorandum and articles of association of HH&L (as may be amended from time to time, the “Cayman Constitutional Documents”), the physical location of the extraordinary general meeting shall be at the offices of White & Case LLP at 1221 Avenue of the Americas, New York, New York 10020, or you or your proxyholder will be able to attend and vote at the extraordinary general meeting online by visiting https://www.cstproxy.com/hhlacquisition/2022 and using a control number assigned by Continental Stock Transfer & Trust Company. To register and receive access to the extraordinary general meeting, registered shareholders and beneficial shareholders (those holding shares through a stock brokerage account or by a bank or other holder of record) will need to follow the instructions applicable to them provided in the accompanying proxy statement / prospectus.

At the extraordinary general meeting, HH&L shareholders will be asked to consider and vote upon various proposals, including, among others, a proposal to approve and adopt the Business Combination Agreement, dated as of October 14, 2022 (as may be amended from time to time, the “Merger Agreement”), by and among HH&L, Diamond Merger Sub Inc. (“Merger Sub”), a Delaware corporation and direct wholly owned subsidiary of HH&L, and DiaCarta, Ltd., a Cayman Islands exempted company incorporated with limited liability (“DiaCarta” and, after the DiaCarta Domestication as described below, “Domesticated DiaCarta”), which will domesticate (such domestication, the “DiaCarta Domestication”) as a Delaware corporation prior to the Merger (as defined below), a copy of which is attached to the accompanying proxy statement / prospectus as Annex A (the “BCA Proposal”). The Merger Agreement provides for, among other things, following the HH&L Domestication and DiaCarta Domestication, the merger of Merger Sub with and into Domesticated DiaCarta (the “Merger”), with Domesticated DiaCarta surviving the Merger as a wholly owned subsidiary of DiaCarta PubCo, in accordance with the terms and subject to the conditions of the Merger Agreement as more fully described elsewhere in the accompanying proxy statement / prospectus.

As a condition to the consummation of the Merger, the board of directors of HH&L has unanimously approved a change of HH&L’s jurisdiction of incorporation by deregistering as an exempted company in the Cayman Islands and continuing and domesticating as a corporation incorporated under the laws of the State of Delaware (the “HH&L Domestication” and, together with the Merger, the “Business Combination”). As described in this proxy statement / prospectus, you will be asked to consider and vote upon a proposal to approve the HH&L Domestication (the “Domestication Proposal”). In connection with the consummation of the Business Combination, HH&L will change its name to “DiaCarta, Inc.”.

In connection with the HH&L Domestication, (1) each of the then issued and outstanding 10,350,000 Class B ordinary shares, par value $0.0001 per share, of HH&L (the “HH&L Class B ordinary shares”) shall, immediately prior to the HH&L Domestication, convert automatically into a HH&L Class A ordinary share (as defined below) (subject to adjustment of the conversion ratio as provided by the terms of the Cayman Constitutional Documents, as applicable), in accordance with and pursuant to the approvals to be obtained from the shareholders of HH&L, including the approval of the requisite majority of the holders of HH&L Class B ordinary shares, (2) immediately following the conversion described in clause (1), each of the then issued and outstanding 51,750,000 Class A ordinary shares, par value $0.0001 per share, of HH&L (the “HH&L Class A ordinary shares”) (including those Class A ordinary shares resulting from the conversion described in clause (1) and those Class A ordinary shares underlying the HH&L units (as defined below)), shall convert automatically, on a one-for-one basis, into a share of common stock, par value $0.0001 per share, of DiaCarta PubCo (the “DiaCarta PubCo common stock”), (3) each of the then issued and outstanding 30,980,000 redeemable warrants of HH&L (the “HH&L warrants”) (including those warrants underlying the HH&L units) will convert automatically into a redeemable warrant to acquire one share of DiaCarta PubCo common stock (the “DiaCarta PubCo warrants”) pursuant to the Warrant Agreement, dated February 5, 2021 (the “Warrant Agreement”), between HH&L and Continental Stock Transfer & Trust Company (“Continental”), as warrant agent, and (4) each of the then issued and outstanding units of HH&L (the “HH&L units”) that have not been previously

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separated into the underlying HH&L Class A ordinary shares and underlying HH&L warrants upon the request of the holder thereof, will convert into a unit of DiaCarta PubCo (the “DiaCarta PubCo units”), with each DiaCarta PubCo unit representing one share of DiaCarta PubCo common stock and one-half (1/2) of one DiaCarta PubCo warrant. Upon the closing of the Business Combination, immediately prior to the effective time of the Merger, each issued and outstanding DiaCarta PubCo unit immediately prior to the effective time will be automatically separated and the holder thereof shall be deemed to hold one share of DiaCarta PubCo common stock and one-half (1/2) of one DiaCarta PubCo warrant. No fractional DiaCarta PubCo warrants will be issued upon separation of the DiaCarta PubCo units. As used herein, “public shares” shall mean the HH&L Class A ordinary shares (including those underlying the HH&L units) that were registered pursuant to the Registration Statement on Form S-1 (333-252254) and the shares of DiaCarta PubCo common stock issued as a matter of law upon the conversion thereof on the effective date of the HH&L Domestication. For further details, see “Domestication Proposal.”

You will be asked to consider and vote upon (1) the BCA Proposal and (2) the Domestication Proposal as mentioned above, each to be approved by special resolution. In addition, you will also be asked to consider and vote upon (3) a proposal to approve by special resolution the automatic conversion, immediately prior to the HH&L Domestication, of each of the then issued 10,350,000 HH&L Class B ordinary shares into a HH&L Class A ordinary share (subject to adjustment of the conversion ratio as provided by the terms of the Cayman Constitutional Documents (the “Class B Conversion Proposal”)), (4) a proposal to approve by special resolution the proposed new certificate of incorporation (the “Proposed Certificate of Incorporation”) and the proposed new bylaws (the “Proposed Bylaws”, and together with the Proposed Certificate of Incorporation, the “Proposed Organizational Documents”) of DiaCarta PubCo (the “Organizational Documents Proposal”), (5) four separate proposals to approve, by special resolutions, material differences between the Cayman Constitutional Documents and the Proposed Certificate of Incorporation and the Proposed Bylaws (collectively, the “Advisory Organizational Documents Proposals”), (6) a proposal, to approve by way of ordinary resolutions, the election of five directors, who, upon consummation of the Business Combination, will constitute all the members of the board of directors of DiaCarta PubCo, each to serve a term set forth under the Proposed Organizational Documents or until such director’s earlier death, resignation, retirement or removal (the “Director Election Proposal”), (7) a proposal, to approve by ordinary resolution, for purposes of complying with the applicable provisions of NYSE Listing Rule 312.03, the issuance of shares of DiaCarta PubCo common stock in connection with the Business Combination (the “Stock Issuance Proposal”), (8) a proposal to approve by ordinary resolution and adopt the DiaCarta, Inc. 2022 Equity Incentive Plan (the “Equity Incentive Plan Proposal”), and (9) a proposal to approve by ordinary resolution the adjournment of the extraordinary general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies in the event that there are insufficient votes for the approval of one or more proposals at the extraordinary general meeting (the “Adjournment Proposal”). The Business Combination will be consummated only if the BCA Proposal, the Domestication Proposal, the Class B Conversion Proposal, the Organizational Documents Proposal, the Advisory Organizational Documents Proposals, the Director Election Proposal, the Stock Issuance Proposal and the Equity Incentive Plan Proposal (collectively, the “Condition Precedent Proposals”) are approved at the extraordinary general meeting. Each of the Condition Precedent Proposals is cross-conditioned on the approval of each other. The Adjournment Proposal is not conditioned upon the approval of any other proposal. Each of these proposals is more fully described in the accompanying proxy statement / prospectus, which each shareholder is encouraged to read carefully and in its entirety.

In connection with the DiaCarta Domestication, (1) each of the then issued and outstanding 28,489,472 ordinary shares, par value $0.001 per share, of DiaCarta (the “DiaCarta ordinary shares”) will convert, on a one-for-one basis, into a share of common stock, par value $0.0001 per share, of Domesticated DiaCarta (the “Domesticated DiaCarta common stock”); (2) each of the then issued and outstanding 7,543,978 Series A Preference Shares, par value $0.001 per share, of DiaCarta (the “DiaCarta Series A Preference Shares”) will convert, on a one-for-one basis, into a share of Domesticated DiaCarta common stock; (3) each of the then issued and outstanding 12,183,137 Series B Preference Shares, par value $0.001 per share, of DiaCarta (the “DiaCarta Series B Preference Shares”) will convert, on a one a one-for-one basis, into a share of Domesticated DiaCarta common stock; (4) each of the then outstanding options to purchase DiaCarta ordinary shares (the “DiaCarta Options”) will convert into an option to acquire, on a one-for-one basis and subject to substantially the same terms and conditions as were applicable under such DiaCarta Options immediately before the DiaCarta Domestication, shares of Domesticated DiaCarta common stock (the “Domesticated DiaCarta options”); and (5) each of the then issued and outstanding warrants of DiaCarta to purchase the DiaCarta Series B Preference Shares (the “DiaCarta warrants”) will convert into a warrant to acquire, on a one-for-one basis and subject to substantially the same terms and conditions as were applicable under such DiaCarta warrants immediately before the DiaCarta Domestication, shares of Domesticated DiaCarta common stock (the “Domesticated DiaCarta warrants”).

As a result of and upon the closing of the Business Combination, among other things, each share of Domesticated DiaCarta common stock (after giving effect to the DiaCarta Domestication) issued and outstanding as of immediately prior to the effective time of the Merger will be cancelled in exchange for the right to receive a number of shares of DiaCarta PubCo common stock equal to the Exchange Ratio. “Exchange Ratio” means the quotient obtained by dividing (a) the number of shares (at a deemed value of $10.00 per share) constituting a fully-diluted pre-transaction equity value of DiaCarta of $460 million, by (b) the aggregate number of shares of

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Domesticated DiaCarta common stock that are (i) issued and outstanding immediately prior to the effective time, and (ii) issuable upon, or subject to, the exercise of Domesticated DiaCarta options or Domesticated DiaCarta warrants (whether or not then vested or exercisable), in each case, that are outstanding immediately prior to the effective time.

At the effective time of the Merger, (1) each Domesticated DiaCarta option outstanding immediately prior to the effective time will be converted into an option to acquire, upon substantially the same terms and conditions as are in effect with respect to such option immediately prior to the effective time, the number of shares of DiaCarta PubCo common stock, determined by multiplying (A) the number of shares of Domesticated DiaCarta common stock subject to such Domesticated DiaCarta option as of immediately prior to the effective time, by (B) the Exchange Ratio, at an exercise price per share of DiaCarta PubCo common stock equal to (i) the exercise price per share of Domesticated DiaCarta common stock of such Domesticated DiaCarta option in effect immediately prior to the effective time, divided by (ii) the Exchange Ratio (each, a “DiaCarta PubCo Option”); and (2) each Domesticated DiaCarta warrant issued and outstanding immediately prior to the effective time will be converted into a warrant to acquire, subject to substantially the same terms and conditions as were applicable under such DiaCarta warrant, the number of shares of DiaCarta PubCo common stock, determined by multiplying (A) the number of shares of Domesticated DiaCarta common stock subject to such Domesticated DiaCarta warrant immediately prior to the effective time, by (B) the Exchange Ratio, at an exercise price per share of DiaCarta PubCo common stock equal to (i) the exercise price per share of Domesticated DiaCarta common stock of such Domesticated DiaCarta warrant divided by (ii) the Exchange Ratio (each, a “Converted DiaCarta PubCo Warrant”). At the effective time of the Merger, DiaCarta PubCo will assume all obligations of Domesticated DiaCarta with respect to the Domesticated DiaCarta options and Domesticated DiaCarta warrants, as converted.

In connection with the Business Combination, certain related agreements have been, or will be entered into on or prior to closing date of the Business Combination, including (i) the HH&L Holders Support Agreement (as defined below), (ii) the DiaCarta Holders Support Agreement (as defined below), (iii) the Registration Rights Agreement (as defined below), (iv) the Lock-Up Agreement (as defined below) and (v) the Sponsor Shares Forfeiture Agreement (as defined below) (collectively, the “Ancillary Agreements”). For additional information, see “BCA Proposal — Related Agreements.”

Pursuant to the Cayman Constitutional Documents, a holder (a “public shareholder”) of public shares, which excludes shares held by HH&L Investment Co. (the “Sponsor”) and the directors and officers of HH&L, may request that HH&L redeem all or a portion of such shareholder’s public shares for cash if the Business Combination is consummated. Holders of units must elect to separate the units into the underlying public shares and warrants prior to exercising redemption rights with respect to the public shares. If holders hold their units in an account at a brokerage firm or bank, holders must notify their broker or bank that they elect to separate the units into the underlying public shares and warrants, or if a holder holds units registered in its own name, the holder must contact the transfer agent directly and instruct it to do so. Public shareholders may elect to redeem their public shares even if they vote “for” the BCA Proposal or any other Condition Precedent Proposals. If the Business Combination is not consummated, the public shares will be returned to the respective holder, broker or bank. If the Business Combination is consummated, and if a public shareholder properly exercises its right to redeem all or a portion of the public shares that it holds and timely delivers the certificates for its shares (if any) along with the redemption forms to Continental, HH&L’s transfer agent, DiaCarta PubCo will redeem such public shares for a per-share price, payable in cash, equal to the pro rata portion of the trust account established at the consummation of HH&L’s initial public offering (the “trust account”), calculated as of two business days prior to the consummation of the Business Combination. For illustrative purposes, as of June 30, 2022, this would have amounted to approximately $10.00 per issued and outstanding public share. If a public shareholder exercises its redemption rights in full, then it will be electing to exchange its public shares for cash and will no longer own public shares. The redemption takes place following the HH&L Domestication and, accordingly, it is shares of DiaCarta PubCo common stock that will be redeemed immediately after consummation of the Business Combination. See “Extraordinary General Meeting of HH&L — Redemption Rights” in the accompanying proxy statement / prospectus for a detailed description of the procedures to be followed if you wish to redeem your public shares for cash.

Notwithstanding the foregoing, a public shareholder, together with any affiliate of such public shareholder or any other person with whom such public shareholder is acting in concert or as a “group” (as defined in Section 13(d)(3) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)), will be restricted from redeeming its public shares with respect to more than an aggregate of 20% of the public shares. Accordingly, if a public shareholder, alone or acting in concert or as a group, seeks to redeem more than 20% of the public shares, then any such shares in excess of that 20% limit would not be redeemed for cash.

The Sponsor and certain directors and officers of HH&L have agreed to, among other things, vote in favor of the BCA Proposal, including adoption of the Merger Agreement, the other documents contemplated thereby and the related transactions contemplated thereby (including the Business Combination), and to waive their redemption rights in connection with the consummation of the Business Combination with respect to any HH&L ordinary shares held by them and subject also to the terms and conditions contemplated by the support agreement, dated as of October 14, 2022, with HH&L and DiaCarta, a copy of which is attached as

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Annex B to this proxy statement / prospectus (the “HH&L Holders Support Agreement”). The Founder Shares held by the Sponsor and such officers and directors will be excluded from the pro rata calculation used to determine the per-share redemption price. As of the date of the accompanying proxy statement / prospectus, the Sponsor and such directors and officers collectively own approximately 20% of the issued and outstanding HH&L ordinary shares.

Pursuant to a Sponsor Shares Forfeiture Agreement, dated as of October 14, 2022, a copy of which is attached to this proxy statement / prospectus as Annex J (the “Sponsor Shares Forfeiture Agreement”), the Sponsor has also agreed to contribute or forfeit certain HH&L Class B ordinary shares owned by itself to facilitate financing after signing of the Merger Agreement and if the total cash available to HH&L at Closing is less than $40 million.

Certain shareholders of DiaCarta have agreed to, among other things, to vote their outstanding ordinary shares and preference shares of DiaCarta in favor of the Merger Agreement and the other documents contemplated thereby and the related transactions contemplated thereby, including the DiaCarta Domestication and the Merger, subject to the terms and conditions contemplated by the support agreement, dated as of October 14, 2022, with HH&L and DiaCarta, a copy of which is attached as Annex C to this proxy statement / prospectus (the “DiaCarta Holders Support Agreement”). The ordinary shares and preference shares of DiaCarta that are owned by such shareholders of DiaCarta and subject to the DiaCarta Holders Support Agreements represent a majority of two-thirds of the outstanding voting power of ordinary shares and preference shares of DiaCarta (on an as-converted basis).

The Merger Agreement provides that the obligations of DiaCarta to consummate the Merger are conditioned on customary closing conditions. If any of such conditions are not met, and such condition are not or cannot be waived under the terms of the Merger Agreement, then the Merger Agreement could terminate and the proposed Business Combination may not be consummated. In addition, pursuant to the Cayman Constitutional Documents, in no event will HH&L redeem public shares in an amount that would cause its net tangible assets to be less than $5,000,001.

The Merger Agreement is subject to the satisfaction or waiver of certain customary closing conditions, including, among others, (i) approval of the Business Combination and related agreements and transactions, including the HH&L Domestication and the DiaCarta Domestication, by the respective shareholders of HH&L and DiaCarta, (ii) effectiveness of the registration statement on Form S-4 of which this proxy statement / prospectus forms a part to be filed by HH&L in connection with the Business Combination, (iii) expiration or termination of the waiting period required by the antitrust authorities (as contemplated by the Merger Agreement), (iv) receipt of approval for listing on the NYSE of the shares of DiaCarta PubCo common stock to be issued in connection with the Merger, (v) that after redemption, HH&L’s net tangible assets shall be no less than $5,000,001 upon the closing of the Business Combination (the “Closing”) and (vi) the absence of certain injunctions. In addition, DiaCarta’s obligations to consummate the Merger are also conditioned on customary closing conditions. There can be no assurance that the parties to the Merger Agreement would waive any such provision of the Merger Agreement.

The HH&L units, HH&L Class A ordinary shares and public warrants are currently listed on the New York Stock Exchange (the “NYSE”) under the symbols “HHLA.U,” “HHLA” and “HHLA WS,” respectively. HH&L will apply for listing, to be effective at the time of the Business Combination, of DiaCarta PubCo common stock and DiaCarta PubCo warrants on the NYSE under the proposed symbols “ ” and “ ”, respectively. DiaCarta PubCo will not have units traded. It is a condition of the consummation of the Business Combination that HH&L receives confirmation from the NYSE that the securities have been approved for listing on the NYSE, but there can be no assurance such listing conditions will be met or that HH&L will obtain such confirmation from the NYSE. If such listing conditions are not met or if such confirmation is not obtained, the Business Combination will not be consummated unless the NYSE listing condition set forth in the Merger Agreement is waived.

HH&L is providing the accompanying proxy statement / prospectus and accompanying proxy card to HH&L’s shareholders in connection with the solicitation of proxies to be voted at the extraordinary general meeting and at any adjournments of the extraordinary general meeting. Information about the extraordinary general meeting, the Business Combination and other related business to be considered by HH&L’s shareholders at the extraordinary general meeting is included in the accompanying proxy statement / prospectus. Whether or not you plan to attend the extraordinary general meeting, all of HH&L’s shareholders are urged to read the accompanying proxy statement / prospectus, including the Annexes and other documents referred to therein, carefully and in their entirety. You should also carefully consider the risk factors described under the heading “Risk Factors” beginning on page 61 of this proxy statement / prospectus.

After careful consideration, the board of directors of HH&L has unanimously approved the Business Combination and unanimously recommends that shareholders vote “FOR” the BCA Proposal, including adoption of the Merger Agreement, and approval of the transactions contemplated thereby, including the Business Combination, and “FOR” all other proposals presented to HH&L’s shareholders in the accompanying proxy statement / prospectus. When you consider the

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recommendation of these proposals by the board of directors of HH&L, you should keep in mind that HH&L’s directors and officers have interests in the Business Combination that may conflict with your interests as a shareholder. See “BCA Proposal — Interests of HH&L’s Directors and Executive Officers in the Business Combination” in the accompanying proxy statement / prospectus for a further discussion of these considerations.

The approval of each of the BCA Proposal, the Class B Conversion Proposal, the Domestication Proposal, the Organizational Documents Proposal and the Advisory Organizational Documents Proposals requires the affirmative vote of holders of a majority of at least two-thirds of the HH&L ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting. The approval of each of the Director Election Proposal, the Stock Issuance Proposal, the Equity Incentive Plan Proposal, and the Adjournment Proposal require the affirmative vote of a majority of the HH&L ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting.

Your vote is very important. Whether or not you plan to attend the extraordinary general meeting, please vote as soon as possible by following the instructions in the accompanying proxy statement / prospectus to make sure that your shares are represented at the extraordinary general meeting. If you hold your shares in “street name” through a bank, broker or other nominee, you will need to follow the instructions provided to you by your bank, broker or other nominee to ensure that your shares are represented and voted at the extraordinary general meeting. The transactions contemplated by the Merger Agreement will be consummated only if the Condition Precedent Proposals are approved at the extraordinary general meeting. Each of the Condition Precedent Proposals is cross-conditioned on the approval of each other. The Adjournment Proposal is not conditioned upon the approval of any other proposal set forth in the accompanying proxy statement / prospectus.

If you sign, date and return your proxy card without indicating how you wish to vote, your proxy will be voted FOR each of the proposals presented at the extraordinary general meeting. If you fail to return your proxy card or fail to instruct your bank, broker or other nominee how to vote, and do not attend the extraordinary general meeting in person, the effect will be, among other things, that your shares will not be counted for purposes of determining whether a quorum is present at the extraordinary general meeting and will not be voted. An abstention or broker non-vote will be counted towards the quorum requirement but will not count as a vote cast at the extraordinary general meeting. If you are a shareholder of record and you attend the extraordinary general meeting and wish to vote in person, you may withdraw your proxy and vote in person.

TO EXERCISE YOUR REDEMPTION RIGHTS, YOU MUST DEMAND IN WRITING THAT YOUR PUBLIC SHARES ARE REDEEMED FOR A PRO RATA PORTION OF THE FUNDS HELD IN THE TRUST ACCOUNT AND TENDER YOUR PUBLIC SHARES TO HH&L’S TRANSFER AGENT AT LEAST TWO BUSINESS DAYS PRIOR TO THE VOTE AT THE EXTRAORDINARY GENERAL MEETING. YOU MAY TENDER YOUR PUBLIC SHARES BY EITHER DELIVERING YOUR SHARE CERTIFICATE TO THE TRANSFER AGENT OR BY DELIVERING YOUR PUBLIC SHARES ELECTRONICALLY USING THE DEPOSITORY TRUST COMPANY’S DWAC (DEPOSIT WITHDRAWAL AT CUSTODIAN) SYSTEM. IF THE BUSINESS COMBINATION IS NOT COMPLETED, THEN THESE PUBLIC SHARES WILL BE RETURNED TO YOU OR YOUR ACCOUNT. IF YOU HOLD THE PUBLIC SHARES IN STREET NAME, YOU WILL NEED TO INSTRUCT THE ACCOUNT EXECUTIVE AT YOUR BANK OR BROKER TO WITHDRAW THE PUBLIC SHARES FROM YOUR ACCOUNT IN ORDER TO EXERCISE YOUR REDEMPTION RIGHTS.

On behalf of the Board of Directors of HH&L Acquisition Co., I would like to thank you for your support and look forward to the successful completion of the Business Combination.

    

Sincerely,

Richard Qi Li

Chief Executive Officer and Director (Principal Executive Officer)

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES REGULATORY AGENCY HAS APPROVED OR DISAPPROVED THE TRANSACTIONS DESCRIBED IN THE ACCOMPANYING PROXY STATEMENT / PROSPECTUS, PASSED UPON THE MERITS OR FAIRNESS OF THE BUSINESS COMBINATION OR RELATED TRANSACTIONS OR PASSED UPON THE ADEQUACY OR ACCURACY OF THE DISCLOSURE IN THE ACCOMPANYING PROXY STATEMENT / PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY CONSTITUTES A CRIMINAL OFFENSE.

The accompanying proxy statement / prospectus is dated                 and is first being mailed to shareholders on or about                 .

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HH&L Acquisition Co.

A Cayman Islands Exempted Company

(Company Incorporation Number 365837)

P.O. Box 309, Ugland House

Grand Cayman

KY1-1104

Cayman Islands

NOTICE OF EXTRAORDINARY GENERAL MEETING

TO BE HELD ON

TO THE SHAREHOLDERS OF HH&L ACQUISITION CO.:

NOTICE IS HEREBY GIVEN that an extraordinary general meeting (the “extraordinary general meeting”) of HH&L Acquisition Co., a Cayman Islands exempted company incorporated with limited liability company incorporation number 365837 (“HH&L”), will be held at                 , Eastern Time, on                 . For the purposes of Cayman Islands law and the second amended and restated memorandum and articles of association of HH&L (the “Cayman Constitutional Documents”), the physical location of the extraordinary general meeting shall be at the offices of White & Case LLP at 1221 Avenue of the Americas, New York, New York 10020, or you or your proxyholder will be able to attend and vote at the extraordinary general meeting online by visiting https://www.cstproxy.com/hhlacquisition/2022 and using a control number assigned by Continental Stock Transfer & Trust Company. To register and receive access to the extraordinary general meeting, registered shareholders and beneficial shareholders (those holding shares through a stock brokerage account or by a bank or other holder of record) will need to follow the instructions applicable to them provided in this proxy statement / prospectus. You are cordially invited to attend the extraordinary general meeting, which will be held for the following purposes:

Proposal No. 1 — The BCA Proposal — to consider and vote upon a proposal to approve by special resolution and adopt the Business Combination Agreement, dated as of October 14, 2022, (as may be amended from time to time, the “Merger Agreement”), by and among HH&L, Diamond Merger Sub Inc. (“Merger Sub”), a Delaware corporation and subsidiary of HH&L, and DiaCarta, Ltd., a Cayman Islands exempted company incorporated with limited liability (“DiaCarta” and, after the DiaCarta Domestication as described below, “Domesticated DiaCarta”), which will domesticate (such domestication, the “DiaCarta Domestication”) as a Delaware corporation prior to the Merger (as defined below, a copy of which is attached to this proxy statement / prospectus as Annex A. The Merger Agreement provides for, among other things, the merger of Merger Sub with and into Domesticated DiaCarta (the “Merger”), with Domesticated DiaCarta surviving the Merger as a wholly owned subsidiary of DiaCarta PubCo (as defined below), in accordance with the terms and subject to the conditions of the Merger Agreement as more fully described elsewhere in this proxy statement / prospectus (the “BCA Proposal”).

The full text of the resolution to be passed is as follows:

RESOLVED, as a special resolution, that (i) the Business Combination Agreement, dated as of October 14, 2022 (as may be amended from time to time, the “Merger Agreement”), by and among the Company, Diamond Merger Sub Inc. (“Merger Sub”), a Delaware corporation and subsidiary of the Company, and DiaCarta, Ltd., a Cayman Islands exempted company incorporated with limited liability (“DiaCarta” and, after the DiaCarta Domestication as described below, “Domesticated DiaCarta”), which will domesticate (such domestication, the “DiaCarta Domestication”) as a Delaware corporation prior to the Merger (as defined below) (a copy of which is attached to the proxy statement / prospectus as Annex A), and the execution thereof by the Company, be approved, ratified and confirmed in all respects, and (ii) each of the transactions and obligations contemplated by or referred to in the Merger Agreement, including without limitation, the merger of Merger Sub with and into Domesticated DiaCarta (the “Merger”), with Domesticated DiaCarta surviving the Merger as a wholly owned subsidiary of the Company, in accordance with the terms and subject to the conditions of the Merger Agreement, be approved, authorized and confirmed in all respects.”

Proposal No. 2 — The Class B Conversion Proposal — to consider and vote upon a proposal to approve by special resolution the conversion of all issued and outstanding HH&L Class B ordinary shares into HH&L Class A ordinary shares immediately prior to the effective time of the HH&L Domestication (as defined below) (the “Class B Conversion Proposal”).

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The full text of the resolution to be passed is as follows:

RESOLVED, as a special resolution, that the automatic conversion, immediately prior to the HH&L Domestication, of each of the then issued and outstanding Class B ordinary shares, par value $0.0001 per share, of the Company, into a Class A ordinary share, par value $0.0001 per share, of the Company (subject to adjustment of the conversion ratio as provided by the terms of the second amended and restated memorandum and articles of association of the Company) be approved and authorised.”

Proposal No. 3 — The Domestication Proposal — to consider and vote upon a proposal to approve by special resolution, (i) the change of HH&L’s jurisdiction of incorporation by deregistering as an exempted company in the Cayman Islands pursuant to Article 49 of the second amended and restated memorandum and articles of association of HH&L and registering by way of continuation and domesticating as a corporation incorporated under the laws of the State of Delaware (the “HH&L Domestication” and, together with the Merger, the “Business Combination”); (ii) conditional upon, and with effect from, the registration of HH&L in the State of Delaware as a corporation incorporated under the laws of the State of Delaware: (a) the registered office of the Company be changed to        ; (b) Corporation Trust Company be instructed to undertake all necessary steps in order to continue the legal existence of the Company in the State of Delaware as a corporation incorporated under the laws of the State of Delaware; and (c) Maples Corporate Services Limited be instructed to file notice of the resolutions relating to the de-registration with the Registrar of Companies in and for the Cayman Islands. The HH&L Domestication will be effected immediately prior to the Merger by HH&L filing a certificate of corporate domestication and the proposed new certificate of incorporation of DiaCarta PubCo (“Proposed Certificate of Incorporation”) with the Secretary of State of Delaware and filing an application to de-register with the Registrar of Companies of the Cayman Islands. Upon the effectiveness of the HH&L Domestication, HH&L will become a Delaware corporation and will change its corporate name to “DiaCarta, Inc.” and all outstanding securities of HH&L will convert to securities of DiaCarta PubCo as described in more detail in the accompanying proxy statement / prospectus (the “Domestication Proposal”).

The full text of the resolution to be passed is as follows:

RESOLVED, as a special resolution, that (a) the Company be de-registered in the Cayman Islands pursuant to Article 49 of the current Second Amended and Restated Memorandum and Articles of Association of the Company and in accordance with Section 206 of the Cayman Islands Companies Act, and be registered by way of continuation as a corporation in the State of Delaware in accordance with Section 388 of the Delaware General Corporation Law (the “HH&L Domestication”); (b) conditional upon, and with effect from, the registration of the Company in the State of Delaware as a corporation under the laws of the State of Delaware, the registered office of the Company be changed to        ; (c) Corporation Trust Company be instructed to undertake all necessary steps in order to continue the legal existence of the Company in the State of Delaware as a corporation incorporated under the laws of the State of Delaware; and (d) Maples Corporate Services Limited be instructed to file notice of the resolutions relating to the de-registration with the Registrar of Companies in and for the Cayman Islands.”

Proposal No. 4 — Organizational Documents Proposal — to consider and vote upon a proposal to approve by special resolution, conditional upon, and with effect from, the registration of HH&L in the State of Delaware as a corporation incorporated under the laws of the State of Delaware: (a) the name of HH&L be changed to “DiaCarta, Inc.”; and (b) the currently effective memorandum and articles of association of HH&L be amended so as to be replaced in their entirety with the proposed new certificate of incorporation (“Proposed Certificate of Incorporation”) and the proposed new bylaws (“Proposed Bylaws” and, together with the Proposed Certificate of Incorporation, the “Proposed Organizational Documents” (copies of which are attached to this proxy statement / prospectus as Annex H and Annex G, respectively)) of the Company (a corporation incorporated in the State of Delaware upon the filing with and acceptance by the Secretary of State of Delaware of the certificate of domestication in accordance with Section 388 of the Delaware General Corporation Law (the “DGCL”)), which will be renamed “DiaCarta, Inc.” in connection with the HH&L Domestication (HH&L after the HH&L Domestication, including after such change of name, is referred to herein as “Domesticated HH&L”) (the “Organizational Documents Proposal”);

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The full text of the resolution to be passed is as follows:

RESOLVED, as a special resolution, that conditional upon, and with effect from, the registration of the Company in Delaware as a Delaware corporation under the laws of Delaware:

a)the name of the Company be changed to “DiaCarta, Inc.”; and
b)the Second Amended and Restated Memorandum and Articles of Association of the Company currently in effect be amended and restated by the deletion in their entirety and the substitution in their place of the Proposed Certificate of Incorporation and Proposed Bylaws (copies of which are attached to the proxy statement / prospectus as Annex H and Annex G, respectively), with such principal changes as described in Advisory Organizational Documents Proposals A – D set out in the resolutions below.”
Proposal No. 5 — Advisory Organizational Documents Proposals — to consider and vote upon the following four separate proposals (collectively, the “Advisory Organizational Documents Proposals”) to approve, by special resolution, the following material differences between the Cayman Constitutional Documents”) and the Proposed Organizational Documents:
(A)Advisory Organizational Documents Proposal 5A — to authorize the change in the authorized share capital of HH&L from (i) 500,000,000 HH&L Class A ordinary shares of a par value of US$0.0001 each, 50,000,000 HH&L Class B ordinary shares of a par value of US$0.0001 each and 5,000,000 HH&L preference shares of a par value of US$0.0001 each to (ii)          shares of DiaCarta PubCo common stock and         shares of DiaCarta PubCo preferred stock (“Advisory Organizational Documents Proposal 5A”);
(B)Advisory Organizational Documents Proposal 5B — to authorize the board of directors of DiaCarta PubCo to issue any or all shares of DiaCarta PubCo preferred stock in one or more classes or series, with such terms and conditions as may be expressly determined by DiaCarta PubCo’s board of directors and as may be permitted by the DGCL (“Advisory Organizational Documents Proposal 5B”);
(C)Advisory Organizational Documents Proposal 5C — to provide that DiaCarta PubCo’s board of directors be divided into three classes with only one class of directors being elected in each year and each class serving a three-year term (“Advisory Organizational Documents Proposal 5C”); and
(D)Advisory Organizational Documents Proposal 5D — to authorize all other changes in connection with the replacement of the Cayman Constitutional Documents with the Proposed Certificate of Incorporation and Proposed Bylaws in connection with the consummation of the Business Combination (copies of which are attached to this proxy statement / prospectus as Annex H and Annex G, respectively), including (1) changing the company name from “HH&L Acquisition Co.” to “DiaCarta, Inc.,” (2) making DiaCarta PubCo’s corporate existence perpetual, (3) adopting Delaware as the exclusive forum for certain stockholder litigation, (4) electing not to be governed by Section 203 of the DGCL and, instead, be governed by a provision substantially similar to Section 203 of the DGCL, (5) removing certain provisions related to HH&L’s status as a blank check company that will no longer be applicable upon consummation of the Business Combination, (6) requiring stockholders to take action at an annual or special meeting and prohibiting stockholder action by written consent in lieu of a meeting, and (7) requiring the affirmative vote of at least two-thirds of the voting power of the outstanding shares to (i) adopt, amend or repeal the Proposed Bylaws, and to (ii) amend, alter, repeal or rescind Articles VII, VIII, IX, X, XI, XII and XIII of the Proposed Certificate of Incorporation, all of which HH&L Board believes is necessary to adequately address the needs of DiaCarta PubCo after the Business Combination (“Advisory Organizational Documents Proposal 5D”).

The full text of the resolutions to be passed are as follows:

“RESOLVED, as a special resolution, conditional upon, and with effect from, the registration of the Company in Delaware as a Delaware corporation under the laws of Delaware, that the authorized share capital of HH&L be changed from (i) 500,000,000 HH&L Class A ordinary shares of a par value of US$0.0001 each, 50,000,000 HH&L Class B ordinary shares of a par value of US$0.0001 each and 5,000,000 HH&L preference shares of a par value of US$0.0001 each to (ii)         shares of DiaCarta PubCo common stock and          shares of DiaCarta PubCo preferred stock;

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RESOLVED, as a special resolution, conditional upon, and with effect from, the registration of the Company in Delaware as a Delaware corporation under the laws of Delaware, that the board of directors of DiaCarta PubCo be authorized to issue any or all shares of DiaCarta PubCo preferred stock in one or more classes or series, with such terms and conditions as may be expressly determined by DiaCarta PubCo’s board of directors and as may be permitted by the DGCL;

RESOLVED, as a special resolution, conditional upon, and with effect from, the registration of the Company in Delaware as a Delaware corporation under the laws of Delaware, that DiaCarta PubCo’s board of directors be divided into three classes with only one class of directors being elected in each year and each class serving a three-year term; and

RESOLVED, as a special resolution, conditional upon, and with effect from, the registration of the Company in Delaware as a Delaware corporation under the laws of Delaware, that all other changes in connection with the replacement of the Cayman Constitutional Documents with the Proposed Certificate of Incorporation and Proposed Bylaws in connection with the consummation of the Business Combination (copies of which are attached to this proxy statement / prospectus as Annex H and Annex G, respectively) be authorized, including (1) changing the company name from “HH&L Acquisition Co.” to “DiaCarta, Inc.,” (2) making DiaCarta PubCo’s corporate existence perpetual, (3) adopting Delaware as the exclusive forum for certain stockholder litigation, (4) electing not to be governed by Section 203 of the DGCL and, instead, be governed by a provision substantially similar to Section 203 of the DGCL, (5) removing certain provisions related to HH&L’s status as a blank check company that will no longer be applicable upon consummation of the Business Combination, (6) requiring stockholders to take action at an annual or special meeting and prohibiting stockholder action by written consent in lieu of a meeting and (7) requiring the affirmative vote of at least two-thirds of the voting power of the outstanding shares to (i) adopt, amend or repeal the Proposed Bylaws, and to (ii) amend, alter, repeal or rescind Articles VII, VIII, IX, X, XI, XII and XIII of the Proposed Certificate of Incorporation, all of which HH&L Board believes is necessary to adequately address the needs of DiaCarta PubCo after the Business Combination.”

Proposal No. 6 — The Director Election Proposal — to consider and vote upon a proposal to approve, by way of ordinary resolution, the election of five directors, who, upon consummation of the Business Combination, will constitute all members of the board of directors of DiaCarta PubCo, each to serve for a term as set forth under the Proposed Organizational Documents or until such director’s earlier death, resignation, retirement, or removal (the “Director Election Proposal”);

The full text of the resolution to be passed is as follows:

RESOLVED, as an ordinary resolution, that the persons named below be elected to serve on DiaCarta PubCo’s board of directors following the consummation of the Business Combination, to serve in the class indicated:

Names of Directors:  Dr. Aiguo (Adam) Zhang and Jack Kaye (Class III, term expiring at the annual meeting to be held in 2025); Paul Okunieff and Kenneth W. Hitchner (Class II, term expiring at the annual meeting to be held in 2024); and          (Class I, term expiring at the annual meeting to be held in 2023).”

Proposal No. 7 — The Stock Issuance Proposal — to consider and vote upon a proposal to approve by ordinary resolution for purposes of complying with the applicable provisions of NYSE Listing Rule 312.03, the issuance of shares of DiaCarta PubCo common stock in connection with the Business Combination (the “Stock Issuance Proposal”);

The full text of the resolution to be passed is as follows:

RESOLVED, as an ordinary resolution, that, for the purposes of complying with the applicable provisions of Section 312.03 of the NYSE’s Listed Company Manual, the issuance of shares of DiaCarta PubCo common stock pursuant to the Merger Agreement, including to the stockholders of Domesticated DiaCarta, be approved in all respects.”

Proposal No. 8 — The Equity Incentive Plan Proposal — to consider and vote upon a proposal to approve by ordinary resolution the DiaCarta, Inc. 2022 Equity Incentive Plan (the “Equity Incentive Plan Proposal”);

The full text of the resolution to be passed is as follows:

RESOLVED, as an ordinary resolution, that the Company’s adoption of the DiaCarta, Inc. 2022 Equity Incentive Plan and any form award agreements thereunder, be approved, ratified and confirmed in all respects.”

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Proposal No. 9 — The Adjournment Proposal — to consider and vote upon a proposal to approve by ordinary resolution the adjournment of the extraordinary general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies in the event that there are insufficient votes for the approval of one or more proposals at the extraordinary general meeting (the “Adjournment Proposal”).

The full text of the resolution to be passed is as follows:

RESOLVED, as an ordinary resolution, that the adjournment of the extraordinary general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies in the event that there are insufficient votes for the approval of one or more proposals at the extraordinary general meeting be approved.”

Each of Proposals No. 1, 2, 3, 4, 5, 6, 7 and 8 is cross-conditioned on the approval of each other. The Adjournment Proposal is not cross-conditioned upon the approval of any other proposal set forth in this proxy statement / prospectus.

These items of business are described in this proxy statement / prospectus, which we encourage you to read carefully and in its entirety before voting.

Only holders of record of HH&L ordinary shares at the close of business on                  are entitled to notice of and to vote at and to have their votes counted at the extraordinary general meeting and any adjournment of the extraordinary general meeting.

This proxy statement / prospectus and accompanying proxy card is being provided to HH&L’s shareholders in connection with the solicitation of proxies to be voted at the extraordinary general meeting and at any adjournment of the extraordinary general meeting. Whether or not you plan to attend the extraordinary general meeting, all of HH&L’s shareholders are urged to read this proxy statement / prospectus, including the Annexes and the documents referred to herein, carefully and in their entirety. You should also carefully consider the risk factors described under the heading “Risk Factorsbeginning on page 61 of this proxy statement / prospectus.

After careful consideration, the board of directors of HH&L has unanimously approved the Business Combination and unanimously recommends that shareholders vote “FOR” the BCA Proposal, including adoption of the Merger Agreement, and approval of the transactions contemplated thereby, including the Business Combination, and “FOR” all other proposals presented to HH&L’s shareholders in this proxy statement / prospectus. When you consider the recommendation of these proposals by the board of directors of HH&L, you should keep in mind that HH&L’s directors and officers have interests in the Business Combination that may conflict with your interests as a shareholder. See “BCA Proposal — Interests of HH&L’s Directors and Executive Officers in the Business Combination” in this proxy statement / prospectus for a further discussion of these considerations.

Pursuant to the Cayman Constitutional Documents, a holder of public shares (as defined herein) (a “public shareholder”) may request HH&L that DiaCarta PubCo redeem all or a portion of its public shares for cash if the Business Combination is consummated. As a holder of public shares, you will be entitled to receive cash for any public shares to be redeemed only if you:

(i)(a) hold public shares, or (b) if you hold public shares through units, you elect to separate your units into the underlying public shares and public warrants prior to exercising your redemption rights with respect to the public shares;
(ii)submit a written request to Continental Stock Transfer & Trust Company (“Continental”), HH&L’s transfer agent, that DiaCarta PubCo redeem all or a portion of your public shares for cash; and
(iii)deliver your certificates for public shares (if any) along with the redemption forms to Continental, HH&L’s transfer agent, physically or electronically through The Depository Trust Company (“DTC”).

Holders must complete the procedures for electing to redeem their public shares in the manner described above prior to                 , Eastern Time, on                  (two business days before the extraordinary general meeting) in order for their shares to be redeemed.

Holders of units must elect to separate the units into the underlying public shares and warrants prior to exercising redemption rights with respect to the public shares. If holders hold their units in an account at a brokerage firm or bank, holders must notify their

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broker or bank that they elect to separate the units into the underlying public shares and warrants, or if a holder holds units registered in its own name, the holder must contact Continental, HH&L’s transfer agent, directly and instruct them to do so. Public shareholders may elect to redeem public shares regardless of if or how they vote in respect of the BCA Proposal or any other Condition Precedent Proposal. If the Business Combination is not consummated, the public shares will be returned to the respective holder, broker or bank.

If the Business Combination is consummated, and if a public shareholder properly exercises its right to redeem all or a portion of the public shares that it holds and timely delivers its shares to Continental, HH&L’s transfer agent, DiaCarta PubCo will redeem such public shares for a per-share price, payable in cash, equal to the pro rata portion of the trust account established at the consummation of HH&L’s initial public offering (the “trust account”), calculated as of two business days prior to the consummation of the Business Combination.  For illustrative purposes, as of June 30, 2022, this would have amounted to approximately $10.02 per issued public share.  If a public shareholder exercises its redemption rights in full, then it will be electing to exchange its public shares for cash and will no longer own public shares.  The redemption takes place following the HH&L Domestication and, accordingly, it is shares of DiaCarta PubCo common stock that will be redeemed promptly after consummation of the Business Combination.  See “Extraordinary General Meeting of HH&L — Redemption Rights” in this proxy statement / prospectus for a detailed description of the procedures to be followed if you wish to redeem your public shares for cash.

Notwithstanding the foregoing, a public shareholder, together with any affiliate of such public shareholder or any other person with whom such public shareholder is acting in concert or as a “group” (as defined in Section 13(d)(3) of the Exchange Act, will be restricted from redeeming its public shares with respect to more than an aggregate of 20% of the public shares.  Accordingly, if a public shareholder, alone or acting in concert or as a group, seeks to redeem more than 20% of the public shares, then any such shares in excess of that 20% limit would not be redeemed for cash.

HH&L Investment Co., a Cayman Islands exempted company and shareholder of HH&L (the “Sponsor”), and certain directors and officers of HH&L have agreed to, among other things, vote in favor of the BCA Proposal, including adoption of the Merger Agreement, and the transactions contemplated thereby (including the Business Combination), and to waive their redemption rights in connection with the consummation of the Business Combination with respect to any HH&L ordinary shares held by them, and subject also to the terms and conditions contemplated by the support agreement, dated as of October 14, 2022, with HH&L and DiaCarta, a copy of which is attached to this proxy statement / prospectus as Annex B (the “HH&L Holders Support Agreement”).  The Founder Shares held by the Sponsor and such officers and directors will be excluded from the pro rata calculation used to determine the per-share redemption price. As of the date of the accompanying proxy statement / prospectus, the Sponsor and such directors and officers collectively own approximately 20% of the issued and outstanding HH&L ordinary shares.

Pursuant to the Sponsor Shares Forfeiture Agreement, the Sponsor has also agreed to contribute or forfeit certain HH&L Class B ordinary shares owned by itself to facilitate financing after signing of the Merger Agreement and if the total cash available to HH&L at Closing is less than $40 million.

The Merger Agreement provides that the obligations of DiaCarta to consummate the Merger are conditioned on customary closing conditions. If any of such conditions are not met, and such conditions are not or cannot be waived under the terms of the Merger Agreement, then the Merger Agreement could terminate and the proposed Business Combination may not be consummated. In addition, pursuant to the Cayman Constitutional Documents, in no event will HH&L redeem public shares in an amount that would cause its net tangible assets to be less than $5,000,001.

The Merger Agreement is also subject to the satisfaction or waiver of certain other customary closing conditions as described in the accompanying proxy statement / prospectus. There can be no assurance that the parties to the Merger Agreement would waive any such provision of the Merger Agreement.

The approval of each of the BCA Proposal, the Class B Conversion Proposal, the Domestication Proposal, the Organizational Documents Proposal and the Advisory Organizational Documents Proposals requires the affirmative vote of holders of a majority of at least two-thirds of the HH&L ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting. The approval of each of the Director Election Proposal, the Stock Issuance Proposal, the Equity Incentive Plan Proposal and the Adjournment Proposal requires the affirmative vote of a majority of the HH&L ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting.

Your vote is very important. Whether or not you plan to attend the extraordinary general meeting, please vote as soon as possible by following the instructions in this proxy statement / prospectus to make sure that your public shares are represented at the extraordinary general meeting. If you hold your public shares in “street name” through a bank, broker or other nominee, you will need to follow the instructions provided to you by your bank, broker or other nominee to ensure that

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your public shares are represented and voted at the extraordinary general meeting. The transactions contemplated by the Merger Agreement will be consummated only if the Condition Precedent Proposals are approved at the extraordinary general meeting. Each of the Condition Precedent Proposals is cross-conditioned on the approval of each other. The Adjournment Proposal is not conditioned upon the approval of any other proposal set forth in this proxy statement / prospectus.

If you sign, date and return your proxy card without indicating how you wish to vote, your proxy will be voted FOR each of the proposals presented at the extraordinary general meeting. If you fail to return your proxy card or fail to instruct your bank, broker or other nominee how to vote, and do not attend the extraordinary general meeting in person, the effect will be, among other things, that your public shares will not be counted for purposes of determining whether a quorum is present at the extraordinary general meeting and will not be voted. An abstention or broker non-vote will be counted towards the quorum requirement but will not count as a vote cast at the extraordinary general meeting. If you are a shareholder of record and you attend the extraordinary general meeting and wish to vote in person, you may withdraw your proxy and vote in person.

Your attention is directed to the remainder of the proxy statement / prospectus following this notice (including the Annexes and other documents referred to herein) for a more complete description of the proposed Business Combination and related transactions and each of the proposals. You are encouraged to read this proxy statement / prospectus carefully and in its entirety, including the Annexes and other documents referred to herein. If you have any questions or need assistance voting your ordinary shares, please you may contact Morrow Sodali, our proxy solicitor, by calling (800) 662-5200, or banks and brokers can call at (203) 658-9400, or by emailing HHIA.info@investor.morrowsodali.com. This notice of extraordinary general meeting and the proxy statement / prospectus are available at https://www.cstproxy.com/hhlacquisition/2022.

Thank you for your participation. We look forward to your continued support.

By Order of the Board of Directors of HH&L Acquisition Co.,

    

Richard Qi Li

Chief Executive Officer and Director (Principal Executive Officer)

TO EXERCISE YOUR REDEMPTION RIGHTS, YOU MUST DEMAND IN WRITING THAT YOUR PUBLIC SHARES ARE REDEEMED FOR A PRO RATA PORTION OF THE FUNDS HELD IN THE TRUST ACCOUNT AND TENDER YOUR SHARES TO HH&L’S TRANSFER AGENT AT LEAST TWO BUSINESS DAYS PRIOR TO THE VOTE AT THE EXTRAORDINARY GENERAL MEETING. YOU MAY TENDER YOUR SHARES BY EITHER DELIVERING YOUR SHARE CERTIFICATE TO THE TRANSFER AGENT OR BY DELIVERING YOUR SHARES ELECTRONICALLY USING THE DEPOSITORY TRUST COMPANY’S DWAC (DEPOSIT WITHDRAWAL AT CUSTODIAN) SYSTEM. IF THE BUSINESS COMBINATION IS NOT CONSUMMATED, THEN THESE SHARES WILL BE RETURNED TO YOU OR YOUR ACCOUNT. IF YOU HOLD THE SHARES IN STREET NAME, YOU WILL NEED TO INSTRUCT THE ACCOUNT EXECUTIVE AT YOUR BANK OR BROKER TO WITHDRAW THE SHARES FROM YOUR ACCOUNT IN ORDER TO EXERCISE YOUR REDEMPTION RIGHTS.

Table of Contents

TABLE OF CONTENTS

Page

Summary of the Proxy Statement / Prospectus

34

Selected Historical Financial Information of HH&L

52

Selected Historical Financial Information of DiaCarta

54

Selected Unaudited Pro Forma Condensed Combined Financial Information

56

Comparative Share Information

58

Market Price and Dividend Information

60

Risk Factors

61

Extraordinary General Meeting of HH&L

148

BCA Proposal

155

Class B Conversion Proposal

187

Domestication Proposal

188

Organizational Documents Proposal

195

Advisory Organizational Documents Proposals

197

The Director Election Proposal

208

Stock Issuance Proposal

210

Equity Incentive Plan Proposal

212

Adjournment Proposal

218

U.S. Federal Income Tax Considerations

219

Unaudited Pro Forma Condensed Combined Financial Information

235

Information About HH&L

246

HH&L’s Management’s Discussion and Analysis of Financial Condition and Results of Operations

262

Information About DiaCarta

270

DiaCarta’s Management’s Discussion and Analysis of Financial Condition and Results of Operations

308

Management of DiaCarta PubCo following the Business Combination

325

Executive Compensation of DiaCarta

332

Beneficial Ownership of Securities

337

Certain Relationships and Related Party Transactions

340

Comparison of Corporate Governance and Shareholder Rights

344

Description of DiaCarta PubCo Securities

347

Securities Act Restrictions on Resale of DiaCarta PubCo Securities

350

Shareholder Proposals and Nominations

351

Shareholder Communications

352

Legal Matters

353

Experts

354

Our Transfer Agent and Warrant Agent

355

Delivery of Documents to Shareholders

356

Enforceability of Civil Liability

357

Where You Can Find More Information; Incorporation by Reference

358

Index to Financial Statements

F-1

Annex A Merger Agreement

A-1

Annex B HH&L Holders Support Agreement

B-1

Annex C DiaCarta Holders Support Agreement

C-1

Annex D Form of Registration Rights Agreement

D-1

Annex E Form of DiaCarta, Inc. 2022 Equity Incentive Plan

E-1

Annex F Cayman Constitutional Documents of HH&L

F-1

Annex G Form of Bylaws of DiaCarta, Inc.

G-1

Annex H Form of Certificate of Incorporation of DiaCarta, Inc.

H-1

Annex I Form of Lock-Up Agreement

I-1

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REFERENCES TO ADDITIONAL INFORMATION

This proxy statement / prospectus incorporates important information that is not included in or delivered with this proxy statement / prospectus. This information is available for you to review through the SEC’s website at www.sec.gov.

You may request copies of this proxy statement / prospectus or other information concerning HH&L, without charge, by written request to Richard Qi Li, HH&L Acquisition Co., Suite 2001-2002, 20/F, York House, The Landmark, 15 Queen’s Road Central, Central Hong Kong, Tel: +852 3752 2870; or Morrow Sodali, our proxy solicitor, by calling (800) 662-5200, or banks and brokers can call at (203) 658-9400, or by emailing HHIA.info@investor.morrowsodali.com, or from the SEC through the SEC website at the address provided above.

In order for you to receive timely delivery of the documents in advance of the extraordinary general meeting of HH&L to be held on                , you must request the information no later than four business days prior to the date of the extraordinary general meeting, by                 .

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ABOUT THIS DOCUMENT

This document, which forms part of a registration statement on Form S-4 filed with the SEC by HH&L, constitutes a prospectus of HH&L under Section 5 of the Securities Act of 1933, as amended (the “Securities Act”), with respect to the shares of common stock and warrants of HH&L to be issued to HH&L’s stockholders pursuant to the HH&L Domestication and to DiaCarta’s stockholders under the Merger Agreement. This document also constitutes a proxy statement of HH&L under Section 14(a) of the Exchange Act.

You should rely only on the information contained or incorporated by the reference into this proxy statement / prospectus. No one has been authorized to provide you with information that is difference from that contained in, or incorporated by reference into, this proxy statement / prospectus. This proxy statement / prospectus is dated as of the date set forth on the cover hereof. You should not assume that the information contained in this proxy statement / prospectus is accurate as of any date other than that date. You should not assume that the information incorporated by reference into this proxy statement / prospectus is accurate as of any date other than the date of such incorporated document. Neither the mailing of this proxy statement / prospectus to HH&L shareholders nor the issuance by HH&L of its securities in connection with the Business Combination will create any implication to the contrary.

Information contained in this proxy statement / prospectus regarding HH&L has been provided by HH&L and information contained in this proxy statement / prospectus regarding DiaCarta has been provided by DiaCarta.

This proxy statement / prospectus does not constitute an offer to sell or a solicitation of an offer to buy any securities, or the solicitation of a proxy, in any jurisdiction to or from any person to whom it is unlawful to make any such offer or solicitation in such jurisdiction.

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MARKET AND INDUSTRY DATA

This proxy statement / prospectus contains information concerning the market and industry in which DiaCarta conducts its business. DiaCarta operates in an industry in which it is difficult to obtain precise industry and market information. DiaCarta has obtained market and industry data in this proxy statement / prospectus from industry publications and from surveys or studies conducted by third parties that it believes to be reliable. DiaCarta cannot assure you of the accuracy and completeness of such information, and it has not independently verified the market and industry data contained in this proxy statement / prospectus or the underlying assumptions relied on therein. As a result, you should be aware that any such market, industry and other similar data may not be reliable. Industry and market data is subject to change and cannot always be verified with complete certainty due to limits on availability and reliability of raw data, the voluntary nature of data gathering process and other limitations and uncertainties inherent in any statistical survey. While DiaCarta is not aware of any misstatements regarding any industry data presented in this proxy statement / prospectus, such data involves risks and uncertainties and is subject to change based on various factors, including those discussed under the section entitled “Risk Factors” below.

You also may obtain additional proxy cards and other information related to the proxy solicitation by contacting the appropriate contact listed above. You will not be charged for any of these documents that you request.

For a more detailed description of the information incorporated by reference in this proxy statement / prospectus and how you may obtain it, see “Where You Can Find More Information” beginning on page 358.

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SELECTED DEFINITIONS

Unless otherwise stated or unless the context otherwise requires the terms “we,” “us,” “our” and “HH&L” refer to HH&L Acquisition Co., and the terms “DiaCarta, Ltd.,” “Combined Company” and “post-combination company” refer to DiaCarta, Ltd. and its subsidiaries following the consummation of the Business Combination.

Unless otherwise stated in this proxy statement / prospectus or the context otherwise requires, references to:

“2022 Plan” are to the DiaCarta, Inc. 2022 Equity Incentive Plan attached to this proxy statement / prospectus as Annex E;
“Aggregate Merger Consideration” are to a number of the shares of DiaCarta PubCo common stock equal to the quotient obtained by dividing $460 million by $10.00;
“Ancillary Agreements” are to, collectively, the HH&L Holders Support Agreement, the DiaCarta Holders Support Agreement, the Registration Rights Agreement, the Lock-Up Agreement and the Sponsor Shares Forfeiture Agreement;
“Business Combination” are to the HH&L Domestication together with the Merger;
“Cayman Constitutional Documents” are to HH&L’s Second Amended and Restated Memorandum and Articles of Association attached to this proxy statement / prospectus as Annex F, as amended from time to time;
“Cayman Islands Companies Act” are to the Cayman Islands Companies Act (As Revised);
“CFIUS” are to the Committee on Foreign Investment in the United States;
“Closing” are to the closing of the Business Combination;
“Closing Date” are to the date of closing of the Business Combination;
“Company,” “we,” “us” and “our” are to HH&L prior to its domestication as a corporation in the State of Delaware and to DiaCarta PubCo after its domestication as a corporation incorporated in the State of Delaware, including after its change of name to DiaCarta, Inc.;
“Condition Precedent Approvals” are to the approval at the extraordinary general meeting of the Condition Precedent Proposals;
“Condition Precedent Proposals” are to the BCA Proposal, the Class B Conversion Proposal, the Domestication Proposal, the Class B Conversion Proposal, the Organizational Documents Proposal, the Advisory Organizational Documents Proposals, the Director Election Proposal, the Stock Issuance Proposal and the Equity Incentive Plan Proposal, collectively;
“Continental” are to Continental Stock Transfer & Trust Company;
“Converted DiaCarta PubCo Warrants” are to the warrants of DiaCarta PubCo to purchase the common stock of DiaCarta PubCo, which are converted from DiaCarta warrants automatically at the effective time of the Merger;
“COVID-19 Measures” are to any quarantine, “shelter in place,” “stay at home,” workforce reduction, social distancing, shut down, closure, sequester, safety or similar law, directive, guidelines or recommendations promulgated by any industry group or any governmental authority, including the Centers for Disease Control and Prevention and the World Health Organization, in each case, in connection with or in response to COVID-19, including the CARES Act and Families First Act;
“DGCL” are to the General Corporation Law of the State of Delaware;
“DiaCarta” are to DiaCarta, Ltd. prior to the DiaCarta Domestication, and to Domesticated DiaCarta from and after the DiaCarta Domestication, which will become a wholly owned subsidiary of DiaCarta PubCo as a result of the Business Combination and change its name from DiaCarta, Ltd. to DiaCarta Holdings, Inc.;

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“DiaCarta Domestication” are to a change of DiaCarta’s jurisdiction of incorporation by deregistering as an exempted company in the Cayman Islands and continuing and domesticating as a corporation incorporated under the laws of the State of Delaware;
“DiaCarta Holders Support Agreement” are to that certain support agreement, dated October 14, 2022, by and among DiaCarta, HH&L, and certain shareholders of DiaCarta as set forth therein attached to this proxy statement / prospectus as Annex B, as amended and modified from time to time;
“DiaCarta Incentive Plan” are to (i) the 2021 Share Incentive Plan of DiaCarta, as amended from time to time in connection with the DiaCarta Domestication. and (ii) the non-qualified stock option award to purchase 40,000 DiaCarta ordinary shares outside of the 2021 Share Incentive Plan;
“DiaCarta Note and Warrant Purchase Agreement” are to the Note and Warrant Purchase Agreement, dated as of July 7, 2020, by and between DiaCarta and Ultragenyx Pharmaceutical Inc.;
“DiaCarta Options” are to options to purchase DiaCarta ordinary shares granted under the DiaCarta Incentive Plan;
“DiaCarta ordinary shares” are to ordinary shares of DiaCarta, par value $0.001 per share;
“DiaCarta preference shares” are to DiaCarta preference shares, of which (A) 7,543,978 shares are designated as Series A Preference Shares (“DiaCarta Series A Preference Shares”), par value $0.001 per share, all of which are issued and outstanding, and (B) 13,646,217 shares are designated as Series B Preference Shares (“DiaCarta Series B Preference Shares”), par value $0.001 per share, of which 12,183,137 shares are issued and outstanding;
“DiaCarta Preference Conversion” are to the conversion, in connection with the DiaCarta Domestication, of (i) each issued and outstanding DiaCarta Series A Preference Share, on a one-for-one basis, into one share of Domesticated DiaCarta common stock, and (ii) each issued and outstanding DiaCarta Series B Preference Share, on a one-for-one basis, into one share of Domesticated DiaCarta common stock;
“DiaCarta PubCo” are to HH&L after the HH&L Domestication and its name change from HH&L Acquisition Co. to DiaCarta, Inc.;
“DiaCarta PubCo common stock” are to the common stock, par value $0.0001 per share, of DiaCarta PubCo;
“DiaCarta PubCo Options” are to options to acquire shares of DiaCarta PubCo common stock;
“DiaCarta PubCo warrants” are to the warrants of DiaCarta PubCo to purchase shares of common stock of DiaCarta PubCo, each whole warrant entitling the holder thereof to acquire one share of DiaCarta PubCo common stock at a price of $11.50 per share, pursuant to the Warrant Agreement, dated February 5, 2021, between HH&L and Continental, as warrant agent;
“DiaCarta shares” are to DiaCarta ordinary shares and DiaCarta preference shares; “DiaCarta warrants” are to the outstanding warrants of DiaCarta to purchase the DiaCarta Series B Preference Shares issued by DiaCarta pursuant to the DiaCarta Note and Warrant Purchase Agreement;
“Domesticated DiaCarta” are to DiaCarta after the DiaCarta Domestication;
“Domesticated DiaCarta common stock” are to the common stock, par value $0.0001 per share, of Domesticated DiaCarta;
“DTC” means the Depository Trust Company;
“EBITDA” means earnings before interest, taxes, depreciation and amortization;
“Exchange Act” are to the Securities Exchange Act of 1934, as amended;

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“Exchange Ratio” are to the quotient obtained by dividing (a) the number of shares constituting the Aggregate Merger Consideration, by (b) the aggregate number of shares of Domesticated DiaCarta common stock that are (i) issued and outstanding immediately prior to the effective time of the Merger, and (ii) issuable upon, or subject to, the exercise of Domesticated DiaCarta options or Domesticated DiaCarta warrants (whether or not then vested or exercisable), in each case, that are outstanding immediately prior to the effective time;
“Existing Articles” are to the current second amended and restated articles of association of HH&L;
“Founder Shares” are to the HH&L Class B ordinary shares purchased by the Sponsor in a private placement prior to the initial public offering, and the HH&L Class A ordinary shares that will be issued upon the conversion thereof;
“GAAP” are to accounting principles generally accepted in the United States of America;
“HH&L” are to HH&L Acquisition Co. prior to its domestication as a corporation in the State of Delaware;
“HH&L Board” are to the board of directors of HH&L;
“HH&L Class A ordinary shares” are to HH&L’s Class A ordinary shares, par value $0.0001 per share;
“HH&L Class B ordinary shares” are to HH&L’s Class B ordinary shares, par value $0.0001 per share;
“HH&L Domestication” are to a change of by deregistering as an exempted company in the Cayman Islands and continuing and domesticating as a corporation incorporated in the State of Delaware;
“HH&L Holders Support Agreement” are to that certain support agreement, dated as of October 14, 2022, by and among HH&L, DiaCarta, each officer and director of HH&L and certain other shareholders of HH&L as set forth therein, attached to this proxy statement / prospectus as Annex B, as amended and modified from time to time;
“HH&L Preference Shares” are to HH&L’s preference shares, par value $0.0001 per share;
“HH&L units” and “units” are to the units of HH&L, each unit representing one HH&L Class A ordinary share and one-half (1/2) of one redeemable warrant, each whole warrant entitling the holder thereof to acquire one HH&L Class A ordinary share at a price of $11.50 per share, that were offered and sold by HH&L in its initial public offering and registered pursuant to the IPO registration statement (less the number of units that have been separated into the underlying public shares and underlying warrants upon the request of the holder thereof);
“HSR Act” are to the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended;
“initial public offering” or “IPO” are to HH&L’s initial public offering that was consummated on February 9, 2021;
“IPO registration statement” are to the Registration Statement on Form S-1 (333-252254) filed by HH&L in connection with its initial public offering, which became effective on February 4, 2021;
“IRS” are to the U.S. Internal Revenue Service;
“JOBS Act” are to the Jumpstart Our Business Startups Act of 2012;
“Lock-Up Agreement” are to the lock-up agreement to be entered into at the Closing, by and among DiaCarta PubCo, certain shareholders of HH&L and certain shareholders of DiaCarta named therein attached to this proxy statement / prospectus as Annex I, as amended and modified from time to time;
“Merger” are to the merger of Merger Sub with and into Domesticated DiaCarta, with Domesticated DiaCarta surviving the merger as a wholly owned subsidiary of DiaCarta PubCo;
“Merger Sub” are to Diamond Merger Sub Inc., a Delaware corporation and a wholly owned subsidiary of HH&L;

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“Merger Agreement” is to the Business Combination Agreement, dated as of October 14, 2022 and as may be amended, restated, modified or supplemented from time to time, by and among HH&L, Merger Sub and DiaCarta, attached to this proxy statement / prospectus as Annex A;
“NYSE” are to the New York Stock Exchange;
“ordinary shares” are to the HH&L Class A ordinary shares and the HH&L Class B ordinary shares, collectively;
“Person” are to any individual, firm, corporation, partnership, limited liability company, incorporated or unincorporated association, joint venture, joint stock company, governmental authority or instrumentality or other entity of any kind;
“PRC” means the People’s Republic of China but solely for the purposes of this proxy statement / prospectus, excluding the Hong Kong Special Administrative Region, the Macau Special Administrative Region and Taiwa;
“private placement warrants” are to the HH&L private placement warrants outstanding as of the date of this proxy statement / prospectus or the warrants of DiaCarta PubCo issued as a matter of law upon the conversion thereof at the time of the HH&L Domestication, as context requires;
“pro forma” are to giving pro forma effect to the Business Combination and related transactions;
“Proposed Bylaws” are to the proposed bylaws of DiaCarta PubCo upon the effective date of the HH&L Domestication attached to this proxy statement / prospectus as Annex G;
“Proposed Certificate of Incorporation” are to the proposed certificate of incorporation of DiaCarta PubCo upon the effective date of the HH&L Domestication attached to this proxy statement / prospectus as Annex H;
“Proposed Organizational Documents” are to the Proposed Certificate of Incorporation and the Proposed Bylaws;
“Proposed Transactions” are to the transactions contemplated by the Merger Agreement and the Ancillary Agreements thereto to occur at or immediately prior to the Closing, including the HH&L Domestication and the Merger;
“public shareholders” are to holders of public shares, whether acquired in HH&L’s initial public offering or acquired in the secondary market;
“public shares” are to the HH&L Class A ordinary shares (including those underlying the HH&L units) that were offered and sold by HH&L in its initial public offering and registered pursuant to the IPO registration statement or the shares of DiaCarta PubCo common stock issued as a matter of law upon the conversion thereof at the time of the HH&L Domestication, as context requires;
“public warrants” are to the redeemable warrants (including those underlying the HH&L units) that were offered and sold by HH&L in its initial public offering and registered pursuant to the IPO registration statement or the redeemable warrants of DiaCarta PubCo issued as a matter of law upon the conversion thereof at the time of the HH&L Domestication, as context requires;
“redemption” are to each redemption of public shares for cash pursuant to the Cayman Constitutional Documents;
“Registration Rights Agreement” are to the Registration Rights Agreement to be entered into at Closing, by and among DiaCarta PubCo, Domesticated DiaCarta, the Sponsor, certain stockholders of DiaCarta PubCo and certain stockholders of Domesticated DiaCarta attached to this proxy statement / prospectus as Annex D, as amended and modified from time to time;
“Sarbanes Oxley Act” are to the Sarbanes-Oxley Act of 2002;
“SEC” are to the United States Securities and Exchange Commission;

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“Securities Act” are to the Securities Act of 1933, as amended;
“Sponsor” are to HH&L Investment Co., a Cayman Islands exempted company;
“Sponsor Shares Forfeiture Agreement” are to that certain Sponsor Shares Forfeiture Agreement, dated October 14, 2022, by and among the Sponsor, HH&L and DiaCarta attached to this proxy statement / prospectus as Annex J, as amended and modified from time to time;
“Treasury Regulations” are to the regulations promulgated under the Code by the United States Department of the Treasury (whether in final, proposed or temporary form), as the same may be amended from time to time;
“trust account” are to the trust account established at the consummation of HH&L’s initial public offering at J.P. Morgan Chase Bank, N.A. and maintained by Continental, acting as trustee;
“Trust Agreement” are to the Investment Management Trust Agreement, dated February 5, 2021, by and between HH&L and Continental, as trustee;
“warrants” are to the public warrants and the private placement warrants, collectively; and
“Warrant Agreement” are to the warrant agreement dated February 5, 2021, between HH&L and Continental.

Unless otherwise stated in this proxy statement / prospectus or the context otherwise requires, all references in this proxy statement / prospectus to HH&L Class A ordinary shares, shares of DiaCarta PubCo common stock, convertible notes or warrants include such securities underlying the units.

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CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement / prospectus contains statements that are forward-looking and as such are not historical facts. This includes, without limitation, statements regarding the financial position, business strategy and the plans and objectives of management for future operations, including as they relate to the potential Business Combination, of HH&L. These statements constitute projections, forecasts and forward-looking statements, and are not guarantees of performance. Such statements can be identified by the fact that they do not relate strictly to historical or current facts. When used in this proxy statement / prospectus, words such as “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “plan,” “possible,” “potential,” “predict,” “project,” “should,” “strive,” “would” and similar expressions may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. When HH&L discusses its strategies or plans, including as they relate to the potential Business Combination, it is making projections, forecasts or forward-looking statements. Such statements are based on the beliefs of, as well as assumptions made by and information currently available to, HH&L’s management.

Forward-looking statements in this proxy statement / prospectus may include, for example, statements about:

the benefits of the Business Combination;
HH&L’s ability to complete the Business Combination or, if HH&L does not consummate the Business Combination, any other initial business combination;
satisfaction or waiver (if applicable) of the conditions to the Merger, including, among other things, the satisfaction or waiver of certain customary closing conditions, including, among others, (i) approval of the Business Combination and related agreements and transactions by the respective shareholders of HH&L and DiaCarta, (ii) effectiveness of the registration statement on Form S-4 of which this proxy statement / prospectus forms a part to be filed by HH&L in connection with the Business Combination, (iii) expiration or termination of the waiting period required by the antitrust authorities (as contemplated by the Merger Agreement), (iv) receipt of approval for listing on the NYSE of the shares of DiaCarta PubCo common stock to be issued in connection with the Merger, (v) that after redemption, HH&L’s net tangible assets shall be no less than $5,000,001 upon Closing and (vi) the absence of certain injunctions;
the occurrence of any other event, change or other circumstances that could give rise to the termination of the Merger Agreement;
the projected financial information, anticipated growth rate, and market opportunity of DiaCarta PubCo;
the ability to obtain or maintain the listing of DiaCarta PubCo common stock and DiaCarta PubCo warrants on the NYSE following the Business Combination;
the HH&L’s public securities’ potential liquidity and trading;
HH&L officers and directors allocating their time to other businesses;
the use of proceeds not held in the trust account or available to us from interest income on the trust account balance;
the impact of the regulatory environment and complexities with compliance related to such environment;
factors relating to the business, operations and financial performance of DiaCarta and its subsidiaries, including:
the impact of the COVID-19 pandemic;
DiaCarta’s current or future products may not achieve or maintain sufficient market acceptance;
DiaCarta needs to enhance its disclosure controls and procedures, and internal control over financial reporting;

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If DiaCarta fails to retain sales and marketing personnel or fails to increase our marketing and sales prowess, it may not be able to generate revenue growth;
DiaCarta’s in-house sales function may reduce flexibility and competitiveness;
Healthcare reform measures could impede or prevent the commercial success of DiaCarta’s products and services;
Developing new or improved diagnostic tests is an expensive, speculative and risky endeavor which may not be successful.
Failure to comply with U.S. federal, state, and foreign laboratory licensing requirements and the applicable requirements of the FDA or any other regulatory authority, could cause DiaCarta to lose the ability to perform tests, experience disruptions to its business, or become subject to administrative or judicial sanctions;
Changes in the way that the FDA regulates tests performed by laboratories like DiaCarta could result in delay or additional expense in offering DiaCarta’s tests and tests that it may develop in the future;
DiaCarta and its third-party suppliers must comply with environmental, health and safety laws and regulations, which can be expensive and restrict how DiaCarta or such suppliers do, or interrupt, their business;
Legislative or regulatory reforms may make it more difficult and costly for DiaCarta to obtain regulatory clearance, approval or certification of any future diagnostic tests and to manufacture, market and distribute diagnostic tests after clearance or approval is obtained;
Clinical trials may be necessary to support future product submissions to the FDA. These clinical trials are expensive and will require the enrollment of large numbers of patients, and suitable patients may be difficult to identify and recruit. Delays or failures in our clinical trials will prevent us from commercializing any modified or new diagnostic tests and will adversely affect DiaCarta’s business, operating results, and prospects;
DiaCarta relies on its senior management team and key personnel, and DiaCarta’s business could be harmed if it is unable to attract and retain personnel;
DiaCarta’s billing, collections and claims processing activities are complex and time-consuming; mistakes or delays in transmitting and collecting claims or failure to comply with applicable billing requirements, could have an adverse effect on revenue;
The sizes of the markets for DiaCarta’s diagnostic tests and services and any future diagnostic tests and services may be smaller than estimated and/or may decline’
Recommendations, guidelines, and quality metrics issued by various organizations may significantly affect payers' willingness to cover and healthcare providers' willingness to prescribe DiaCarta’s products;
DiaCarta’s industry is subject to rapid change, which could make its solutions and the diagnostic tests it develops and services it offers, obsolete. If DiaCarta is unable to continue to innovate and improve its diagnostic tests and services, DiaCarta could lose customers or market share;
DiaCarta may face additional costs, loss of revenue, significant liabilities, harm to its brand, decreased use of its products or services and business disruption if there are any security or data privacy breaches or other unauthorized or improper access to its technology systems;
Cost reduction efforts of our customers, purchasing groups and governmental purchasing organizations could have a material adverse effect on DiaCarta’s sales and profitability

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If DiaCarta suffers product liability lawsuits brought against it, DiaCarta may incur substantial liabilities and may be required to limit or halt the marketing and sale of its products and services. The expense and potential unavailability of insurance coverage for liabilities resulting from issues with DiaCarta’s diagnostic tests and services could harm it and negatively impact sales;
Foreign currency fluctuations could adversely affect DiaCarta’s results;
DiaCarta experiences significant payer concentration, with a limited number of customers accounting for a substantial portion of revenues;
DiaCarta’s success could be impaired if it is unable to obtain, maintain and protect our intellectual property rights; and

other factors detailed under the section entitled “Risk Factors.”

The forward-looking statements contained in this proxy statement / prospectus are based on current expectations and beliefs concerning future developments and their potential effects on us or DiaCarta. There can be no assurance that future developments affecting us or DiaCarta will be those that HH&L or DiaCarta have anticipated. These forward-looking statements involve a number of risks, uncertainties (some of which are beyond HH&L’s control or the control of DiaCarta) or other assumptions that may cause actual results or performance to be materially different from those expressed or implied by these forward-looking statements. These risks and uncertainties include, but are not limited to, those factors described under the heading “Risk Factors” beginning on page 61 of this proxy statement / prospectus. Should one or more of these risks or uncertainties materialize, or should any of our assumptions prove incorrect, actual results may vary in material respects from those projected in these forward-looking statements. HH&L and DiaCarta undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as may be required under applicable securities laws.

You should not place undue reliance on these forward-looking statements in deciding how your vote should be cast or in voting your shares on the proposals set out in this proxy statement / prospectus. Before any HH&L shareholder grants its proxy or instructs how its vote should be cast or votes on the proposals to be put to the extraordinary general meeting, such stockholder should be aware that the occurrence of the events described in the “Risk Factors” section and elsewhere in this proxy statement / prospectus may adversely affect us.

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QUESTIONS AND ANSWERS FOR SHAREHOLDERS OF HH&L

The questions and answers below highlight only selected information from this document and only briefly address some commonly asked questions about the proposals to be presented at the extraordinary general meeting, including with respect to the proposed Business Combination. The following questions and answers do not include all the information that is important to HH&L’s shareholders. HH&L urges shareholders to read this proxy statement / prospectus, including the Annexes and the other documents referred to herein, carefully and in their entirety to fully understand the proposed Business Combination and the voting procedures for the extraordinary general meeting, which will be held at                 , Eastern Time, on                 , at the offices of White & Case LLP located at 1221 Avenue of the Americas, New York, NY 10020, or virtually via live webcast. To participate in the extraordinary general meeting, visit https://www.cstproxy.com/hhlacquisition/2022 and enter the 12 digit control number included on your proxy card. You may register for the extraordinary general meeting as early as                 , Eastern Time, on               . If you hold your public shares through a bank, broker or other nominee, you will need to take additional steps to participate in the extraordinary general meeting, as described in this proxy statement.

Q:

Why am I receiving this proxy statement / prospectus?

A:

HH&L shareholders are being asked to consider and vote upon, among other proposals, a proposal to approve and adopt the Merger Agreement and approve the Business Combination.  The Merger Agreement provides for, among other things, the merger of Merger Sub with and into Domesticated DiaCarta, with Domesticated DiaCarta surviving the merger as a wholly owned subsidiary of DiaCarta PubCo, in accordance with the terms and subject to the conditions of the Merger Agreement as more fully described elsewhere in this proxy statement / prospectus.  See “BCA Proposal” for more detail.

A copy of the Merger Agreement is attached to this proxy statement / prospectus as Annex A and you are encouraged to read it in its entirety.

As a condition to the Merger, HH&L will change its jurisdiction of incorporation by effecting a deregistration under section 206 of the Cayman Islands Companies Act and a domestication under Section 388 of the DGCL, pursuant to which HH&L’s jurisdiction of incorporation will be changed from the Cayman Islands to the State of Delaware.  In connection with the HH&L Domestication, (1) each of the then issued and outstanding HH&L Class B ordinary shares shall, immediately prior to the HH&L Domestication, convert automatically into a HH&L Class A ordinary share (subject to adjustment of the conversion ratio as provided by the terms of the Cayman Constitutional Documents, as applicable) in accordance with and pursuant to the approval to be granted by the shareholders of HH&L (and subject to the approval of the holders of HH&L Class B ordinary shares); (2) immediately following the conversion described in clause (1), each of the then issued and outstanding HH&L Class A ordinary shares will convert automatically, on a one-for-one basis, into a share of DiaCarta PubCo common stock; (3) each of the then issued and outstanding HH&L warrants will convert automatically into a DiaCarta PubCo warrant, pursuant to the Warrant Agreement, dated as of February 5, 2021, between HH&L and Continental Stock Transfer & Trust Company; and (4) each of the then issued and outstanding HH&L units that have not been previously separated into the underlying HH&L Class A ordinary shares and underlying HH&L warrants upon the request of the holder thereof, will convert into a unit of DiaCarta PubCo (the “DiaCarta PubCo units”), with each DiaCarta PubCo unit representing one share of DiaCarta PubCo common stock and one-half (1/2) of one DiaCarta PubCo warrant. Upon the closing of the Business Combination, immediately prior to the effective time of the Merger, each issued and outstanding DiaCarta PubCo unit immediately prior to the effective time will be automatically separated and the holder thereof shall be deemed to hold one share of DiaCarta PubCo common stock and one-half (1/2) of one DiaCarta PubCo warrant.  No fractional DiaCarta PubCo warrants will be issued upon separation of the DiaCarta PubCo units.  See “Domestication Proposal” for additional information.

The provisions of the Proposed Organizational Documents will differ materially from the Cayman Constitutional Documents. Please see “What amendments will be made to the current constitutional documents of HH&L?” below.

THE VOTE OF SHAREHOLDERS IS IMPORTANT. SHAREHOLDERS ARE ENCOURAGED TO VOTE AS SOON AS POSSIBLE AFTER CAREFULLY REVIEWING THIS PROXY STATEMENT / PROSPECTUS, INCLUDING EACH OF THE PROPOSALS BEING PRESENTED AT THE MEETING, THE ANNEXES AND THE ACCOMPANYING FINANCIAL STATEMENTS OF HH&L AND DIACARTA, CAREFULLY AND IN ITS ENTIRETY.

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Q:

What proposals are shareholders of HH&L being asked to vote upon?

A:

At the extraordinary general meeting, HH&L is asking holders of ordinary shares to consider and vote upon:

a proposal to approve and adopt by special resolution the Merger Agreement;
a proposal to approve by special resolution the conversion of the HH&L Class B ordinary shares into HH&L Class A ordinary shares;
a proposal to approve by special resolution the HH&L Domestication;
a proposal to approve by special resolution the Proposed Certificate of Incorporation and the Proposed Bylaws;
the following four separate proposals to approve by special resolution, the following material differences between the Cayman Constitutional Documents and the Proposed Organizational Documents:
to authorize the change in the authorized share capital of HH&L from (i) 500,000,000 HH&L Class A ordinary shares, 50,000,000 HH&L Class B ordinary shares and 5,000,000 HH&L Preference Shares to (ii)         shares of DiaCarta PubCo common stock and          shares of DiaCarta PubCo preferred stock;
to authorize the board of directors of DiaCarta PubCo to issue any or all shares of DiaCarta PubCo preferred stock in one or more classes or series, with such terms and conditions as may be expressly determined by DiaCarta PubCo’s board of directors and as may be permitted by the DGCL;
to provide that DiaCarta PubCo’s board of directors be divided into three classes with only one class of directors being elected in each year and each class serving a three-year term; and
to authorize all other changes in connection with the replacement of Cayman Constitutional Documents with the Proposed Certificate of Incorporation and Proposed Bylaws in connection with the consummation of the Business Combination (copies of which are attached to this proxy statement / prospectus as Annex H and Annex G, respectively), including (1) changing the company name from “HH&L Acquisition Co.” to “DiaCarta Inc.,” (2) making DiaCarta PubCo’s corporate existence perpetual, (3) adopting Delaware as the exclusive forum for certain stockholder litigation, (4) electing not to be governed by Section 203 of the DGCL and, instead, be governed by a provision substantially similar to Section 203 of the DGCL, (5) removing certain provisions related to HH&L’s status as a blank check company that will no longer be applicable upon consummation of the Business Combination, (6) requiring stockholders to take action at an annual or special meeting and prohibiting stockholder action by written consent in lieu of a meeting, and (7) requiring the affirmative vote of at least two-thirds of the voting power of the outstanding shares to (i) adopt, amend or repeal the Proposed Bylaws, and to (ii) amend, alter, repeal or rescind Articles VII, VIII, IX, X, XI, XII and XIII of the Proposed Certificate of Incorporation, all of which HH&L Board believes is necessary to adequately address the needs of DiaCarta PubCo after the Business Combination;
a proposal to approve by ordinary resolution the election of five directors, who, upon consummation of the Business Combination, will constitute all members of the board of directors of DiaCarta PubCo;
a proposal to approve by ordinary resolution, for purposes of complying with applicable listing rules of the NYSE, the issuance of shares of DiaCarta PubCo common stock to certain stockholders of DiaCarta pursuant to the Merger Agreement;
a proposal to approve by ordinary resolution the 2022 Plan; and

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a proposal to approve by ordinary resolution the adjournment of the extraordinary general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies in the event that there are insufficient votes for the approval of one or more proposals at the extraordinary general meeting.

If HH&L’s shareholders do not approve each of the Condition Precedent Proposals, then unless certain conditions in the Merger Agreement are waived by the applicable parties to the Merger Agreement, the Merger Agreement could terminate and the Business Combination may not be consummated. See “BCA Proposal,” “Class B Conversion Proposal,” “Domestication Proposal,” “Organizational Documents Proposal,” “Advisory Organizational Documents Proposals,” “Director Election Proposal,” “Stock Issuance Proposal,” and “Equity Incentive Plan Proposal.”

HH&L will hold the extraordinary general meeting to consider and vote upon these proposals. This proxy statement / prospectus contains important information about the Business Combination and the other matters to be acted upon at the extraordinary general meeting. Shareholders of HH&L should read it carefully.

After careful consideration, HH&L Board has determined that the BCA Proposal, the Class B Conversion Proposal, the Domestication Proposal, the Organizational Documents Proposal, each of the Advisory Organizational Documents Proposals, the Director Election Proposal, the Stock Issuance Proposal, the Equity Incentive Plan Proposal, and the Adjournment Proposal are in the best interests of HH&L and its shareholders and unanimously recommends that you vote or give instruction to vote “FOR” each of those proposals.

The existence of financial and personal interests of one or more of HH&L’s directors may result in a conflict of interest on the part of such director(s) between what he, she or they may believe is in the best interests of HH&L and its shareholders and what he, she or they may believe is best for himself, herself or themselves in determining to recommend that shareholders vote for the proposals. In addition, HH&L’s officers have interests in the Business Combination that may conflict with your interests as a shareholder. See “BCA Proposal—Interests of HH&L’s Directors and Executive Officers in the Business Combination” for a further discussion of these considerations.

Q:

Are the proposals conditioned on one another?

A:

Yes. The Business Combination is conditioned on the approval of each of the Condition Precedent Proposals at the extraordinary general meeting. Each of the Condition Precedent Proposals is cross-conditioned on the approval of each other. The Adjournment Proposal is not conditioned upon the approval of any other proposal.

Q:

Why is HH&L proposing the Business Combination?

A:

HH&L was organized to effect a merger, share exchange, asset acquisition, share purchase, reorganization or similar business combination, with one or more businesses or entities.

Based on its due diligence investigations of DiaCarta and the industry in which it operates, including the financial and other information provided by DiaCarta in the course of HH&L’s due diligence investigations, the HH&L Board believes that the Business Combination with DiaCarta is in the best interests of HH&L and its shareholders and presents an opportunity to increase shareholder value. However, there can be no assurances of this. See “BCA Proposal—HH&L Board’s Reasons for the Approval of the Business Combination” for additional information.

Q:

What material positive and negative factors did the HH&L Board consider in connection with the Business Combination?

HH&L Board believes that the Business Combination with DiaCarta presents a unique business combination opportunity and is in the best interests of HH&L and its shareholders. The board of directors considered certain potentially material positive and negative factors in arriving at that conclusion. These factors are discussed in greater detail in the section entitled “BCA Proposal—HH&L Board’s Reasons for the Approval of the Business Combination,” as well as in the sections entitled “Risk Factors—Risks Related to DiaCarta’s Business and Industry.”

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Q:

Did our Board obtain a third-party valuation or fairness opinion in determining whether or not to proceed with the Business Combination?

A:

No. Our Board did not engage any third party valuation expert in determining whether or not to proceed with the Business Combination. Our Board believes that based on the financial skills and background of its directors, it is qualified to conclude the Business Combination was fair from a financial perspective to its shareholders. Our Board also determined, without seeking a valuation from an independent financial advisor, that DiaCarta’s fair market value was at least 80% of HH&L’s net assets, excluding any taxes payable on the interest earned. Accordingly, HH&L shareholders will be relying on the judgement of our Board as described above in valuing DiaCarta’s business and assuming the risk that our Board may not have properly valued such business.

Q:

Are there interests and other conflicts of interests that HH&L’s current officers and directors may have in the Business Combination?

A:

When you consider the recommendation of HH&L Board in favor of approval of the BCA Proposal, you should keep in mind that the Sponsor and HH&L’s directors and executive officers have interests in such proposal that are different from, or in addition to, those of HH&L shareholders and warrant holders generally. These interests include, among other things, the interests listed below:

Prior to HH&L’s initial public offering, the Sponsor purchased 14,375,000 HH&L Class B ordinary shares for an aggregate purchase price of $25,000, or approximately $0.002 per Founder Share, on September 7, 2020. On January 20, 2021, the Sponsor returned 5,750,000 HH&L Class B ordinary shares for no consideration, following which, the Sponsor holds 8,625,000 Founder Shares. On February 4, 2021, the Sponsor transferred an aggregate of 66,000 HH&L Class B ordinary shares to three independent directors. On February 4, 2021, HH&L effected a share dividend of 1,725,000 HH&L Class B ordinary shares, resulting in an aggregate of 10,350,000 HH&L Class B ordinary shares outstanding. On May 19, 2021, the Sponsor transferred 22,000 HH&L Class B ordinary shares to Skyview Enterprises Limited, an affiliate of Derek Sulger, an independent director of HH&L, for his board service for no cash consideration. As of June 30, 2022, the Sponsor held 10,262,000 HH&L Class B ordinary shares. As a result of the significantly lower investment per HH&L Class B ordinary share of the Sponsor as compared with the investment per public share of HH&L’s public shareholders, a transaction which results in an increase in the value of the investment of the Sponsor may result in a decrease in the value of the investment of our public shareholders.
If HH&L does not consummate a business combination by February 9, 2023 (or the Extended Deadline), it would cease all operations except for the purpose of winding up, redeeming all of the outstanding public shares for cash and, subject to the approval of its remaining shareholders and its board of directors, liquidating and dissolving, subject in each case to its obligations under Cayman Islands law to provide for claims of creditors and the requirements of other applicable law. In such event, the 10,262,000 HH&L Class B ordinary shares owned by the Sponsor would be worthless because following the redemption of the public shares, HH&L would likely have few, if any, net assets. Additionally, in such event, the 10,280,000 private placement warrants purchased by the Sponsor simultaneously with the consummation of HH&L’s initial public offering for an aggregate purchase price of $10,280,000 will also expire worthless.
HH&L’s directors and officers, Huanan Yang, Yingjie (Christina) Zhong, Qingjun Jin, Dr. Jingwu Zhang Zang, Professor Frederick Si Hang Ma and Derek Nelsen Sulger, also have a direct or indirect economic interest in the HH&L Class B ordinary shares. The 10,350,000 shares of DiaCarta PubCo common stock into which the 10,350,000 HH&L Class B ordinary shares held by the Sponsor and certain HH&L’s directors and officers will automatically convert in connection with the Merger (including after giving effect to the HH&L Domestication), if unrestricted and freely tradable, would have had an aggregate market value of $       million based upon the closing price of $         per public share on the NYSE on        , 2022, the most recent practicable date prior to the date of this proxy statement / prospectus. However, given that such shares of DiaCarta PubCo common stock will be subject to certain restrictions, including those described elsewhere in this proxy statement / prospectus, HH&L believes such shares have less value. The 10,280,000 DiaCarta PubCo warrants into which the 10,280,000 private placement warrants held by the Sponsor will automatically convert in connection with the Merger (including after giving effect to the HH&L Domestication), if unrestricted and freely tradable, would have had an aggregate

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market value of $        million based upon the closing price of $      per public warrant on the NYSE on        , the most recent practicable date prior to the date of this proxy statement / prospectus. However, given that such DiaCarta PubCo warrants will be subject to certain restrictions, including those described elsewhere in this proxy statement / prospectus, HH&L believes such warrants have less value.
Accordingly, the Sponsor and HH&L’s officers and directors will lose their entire investment of $10,305,000, consisting of the Sponsor’s $25,000 initial investment and the Sponsor’s $10,280,000 private placement warrant purchase price, if HH&L does not complete a business combination by February 9, 2023 (or the Extended Deadline).
Pursuant to that certain letter agreement, dated as of February 5, 2021, by and among the HH&L, its executive officers, its directors, its advisory board members and the Sponsor, in connection with HH&L’s initial public offering, the Sponsor and other signatories (each of whom is a member of HH&L Board, advisory board member and/or executive officers) is subject to certain restrictions on transfer with respect to: (i) HH&L Class B ordinary shares; and (ii) private placement warrants. Such restrictions on the HH&L Class B ordinary shares end on the date that is one year after Closing, or are subject to an early price-based release if: (a) the price of the shares equals or exceeds $12.00 per share for any twenty trading days within any thirty-day trading period at least 150 days after the Business Combination, or (b) HH&L completes a transaction that results in public shareholders having the right to exchange the HH&L Class A ordinary shares for cash, securities or other property. The restrictions on the private placement warrants end on 30 days after the completion of a business combination.
The Sponsor and HH&L’s directors, advisory board members and/or executive officers irrevocably and unconditionally agreed that if HH&L seeks shareholder approval of a proposed Business Combination, then in connection with the proposed Business Combination, such Sponsor and insider shall not elect to cause HH&L to redeem any of the 10,350,000 HH&L Class B ordinary shares and 10,280,000 private placement warrants beneficially owned or owned of record by such Sponsor or insider, or submit any of such securities for redemption, in connection with the transactions contemplated by the Merger Agreement or otherwise.
The Sponsor and HH&L’s officers and directors have agreed to waive their rights to liquidating distributions from the trust account with respect to their Founder Shares if HH&L fails to complete a business combination by February 9, 2023 (or the Extended Deadline).
HH&L’s existing directors and officers will be eligible for continued indemnification and continued coverage under HH&L’s directors’ and officers’ liability insurance policy after the Merger and pursuant to the Merger Agreement.
Following the Closing, the Sponsor would be entitled to the repayment of any working capital loan and advances that have been made to HH&L and remain outstanding. If HH&L does not complete an initial business combination within the required period, HH&L may use a portion of its working capital held outside the trust account to repay the working capital loans, but no proceeds held in the trust account would be used for this purpose. As of the date of this proxy statement / prospectus, HH&L has $500,000 amount of borrowings under an unsecured convertible promissory notes issued to the Sponsor, dated September 15, 2022.
The Sponsor and HH&L’s officers and directors and their affiliates are entitled to reimbursement of out-of-pocket expenses incurred by them related to identifying, investigating, negotiating and completing an initial business combination, including repayment of any other loans and advances made. However, if HH&L fails to consummate a business combination by February 9, 2023 (or the Extended Deadline), they will not have any claim against the trust account for reimbursement. Accordingly, HH&L may not be able to reimburse these expenses if the Business Combination or another business combination is not completed by such date.
Pursuant to the Registration Rights Agreement, the Sponsor, certain of its respective affiliates and certain shareholders of DiaCarta will have customary registration rights, including demand and piggy-back rights, subject to cooperation and cut-

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back provisions with respect to the shares of DiaCarta PubCo common stock and warrants held by such parties following the consummation of the Business Combination.
The Proposed Certificate of Incorporation will contain a provision expressly electing that DiaCarta PubCo will not to be governed by Section 203 (Delaware’s “interested stockholder” statute) of the DGCL, although it will provide other restrictions regarding takeovers by interested stockholders.
Although the Sponsor and its affiliates have committed considerable capital to HH&L, including through its participation in the IPO and its contribution of a portion of the promote for no consideration, if the Business Combination is consummated, taking into account the investments described above, including the promote, it is possible that the Sponsor and its affiliates could realize a positive rate of return on such investments even if other HH&L shareholders experience a negative rate of return following the Business Combination.
The Sponsor will benefit economically from the completion of a Business Combination and may be incentivized to complete an acquisition of a less favorable target company or on terms less favorable to shareholders rather than liquidate. That said, the Sponsor, by pursuing a business combination with a less favorable target company or on terms less favorable to shareholders than what it would normally negotiate, may cause irreparable reputational damage to the Sponsor, which far exceeds to the dollar value of the Founder Shares, and this risk similarly serves as a disincentive from pursuing an unattractive business combination.

Q:

What will the shareholders of DiaCarta receive in return for HH&L’s acquisition of all of the issued and outstanding equity interests of DiaCarta?

A:

In connection with the DiaCarta Domestication, (1) each of the then issued and outstanding 28,489,472 DiaCarta ordinary shares will convert, on a one-for-one basis, into a share of Domesticated DiaCarta common stock; (2) each of the then issued and outstanding 7,543,978 DiaCarta Series A Preference Shares will convert, on a one-for-one basis, into a share of Domesticated DiaCarta common stock; (3) each of the then issued and outstanding 12,183,137 DiaCarta Series B Preference Shares will convert, on a one a one-for-one basis, into a share of Domesticated DiaCarta common stock; (4) each of the then outstanding options to purchase DiaCarta ordinary shares will convert into an option to acquire, on a one-for-one basis and subject to substantially the same terms and conditions as were applicable under such DiaCarta Options immediately before the DiaCarta Domestication, shares of Domesticated DiaCarta common stock (the “Domesticated DiaCarta options”); and (5) each of the then issued and outstanding warrants of DiaCarta to purchase the DiaCarta Series B Preference Shares will convert into a warrant to acquire, on a one-for-one basis and subject to substantially the same terms and conditions as were applicable under such DiaCarta warrants immediately before the DiaCarta Domestication, shares of Domesticated DiaCarta common stock (the “Domesticated DiaCarta warrants”).

As a result of and upon the closing of the Business Combination, among other things, each share of Domesticated DiaCarta common stock (after giving effect to the DiaCarta Domestication) issued and outstanding as of immediately prior to the effective time of the Merger will be cancelled in exchange for the right to receive a number of shares of DiaCarta PubCo common stock equal to the Exchange Ratio. “Exchange Ratio” means the quotient obtained by dividing (a) the number of shares (at a deemed value of $10.00 per share) constituting a fully-diluted pre-transaction equity value of DiaCarta of $460 million, by (b) the aggregate number of shares of Domesticated DiaCarta common stock that are (i) issued and outstanding immediately prior to the effective time, and (ii) issuable upon, or subject to, the exercise of Domesticated DiaCarta options or Domesticated DiaCarta warrants (whether or not then vested or exercisable), in each case, that are outstanding immediately prior to the effective time.

At the effective time of the Merger, (1) each Domesticated DiaCarta option outstanding immediately prior to the effective time will be converted into an option to acquire, upon substantially the same terms and conditions as are in effect with respect to such option immediately prior to the effective time, the number of shares of DiaCarta PubCo common stock, determined by multiplying (A) the number of shares of Domesticated DiaCarta common stock subject to such Domesticated DiaCarta option as of immediately prior to the effective time, by (B) the Exchange Ratio, at an exercise price per share of DiaCarta PubCo common stock equal to (i) the exercise price per share of Domesticated DiaCarta common stock of such Domesticated DiaCarta option in effect immediately prior to the effective time, divided by (ii) the Exchange Ratio; and (2) each Domesticated DiaCarta warrant issued and outstanding immediately prior to the effective time will be converted into a warrant to acquire, subject to substantially

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the same terms and conditions as were applicable under such DiaCarta warrant, the number of shares of DiaCarta PubCo common stock, determined by multiplying (A) the number of shares of Domesticated DiaCarta common stock subject to such Domesticated DiaCarta warrant immediately prior to the effective time, by (B) the Exchange Ratio, at an exercise price per share of DiaCarta PubCo common stock equal to (i) the exercise price per share of Domesticated DiaCarta common stock of such Domesticated DiaCarta warrant divided by (ii) the Exchange Ratio. At the effective time of the Merger, DiaCarta PubCo will assume all obligations of Domesticated DiaCarta with respect to the Domesticated DiaCarta options and Domesticated DiaCarta warrants, as converted. For further details, see “BCA Proposal—The Merger Agreement—Consideration—Aggregate Merger Consideration.”

Q:

What equity stake will current HH&L shareholders and the shareholders of DiaCarta hold in DiaCarta PubCo immediately after the consummation of the Business Combination?

A:

It is anticipated that, following the Business Combination, (1) HH&L’s public shareholders are expected to own approximately 42.3% of the outstanding DiaCarta PubCo common stock, (2) the shareholders of DiaCarta (without taking into account any public shares held by the shareholders of DiaCarta prior to the consummation of the Business Combination) are expected to own approximately 47.1% of the outstanding DiaCarta PubCo common stock and (3) the Sponsor and related parties are expected to collectively own approximately 10.6% of the outstanding DiaCarta PubCo common stock. These percentages assume (i) that no public shareholders exercise their redemption rights in connection with the Business Combination and (ii) (a) the vesting and exercise of all DiaCarta PubCo Options and Converted DiaCarta PubCo Warrants for shares of DiaCarta PubCo common stock (assuming that all DiaCarta PubCo Options and Converted DiaCarta PubCo Warrants are net-settled) and (b) that DiaCarta PubCo issues shares of DiaCarta PubCo common stock as the Aggregate Merger Consideration pursuant to the Merger Agreement, which in the aggregate equal to 46,000,000 shares of DiaCarta PubCo common stock (assuming that all DiaCarta PubCo Options and Converted DiaCarta PubCo Warrants are net-settled and although DiaCarta PubCo Options may, by their terms, be cash-settled, resulting in additional dilution). If the actual facts are different from these assumptions, the percentage ownership retained by the Company’s existing shareholders in the combined company will be different.

The following table illustrates varying ownership levels in DiaCarta PubCo immediately following the consummation of the Business Combination based on the assumptions above.

    

    

    

    Assuming 

    

 

Assuming No

Maximum 

 

Redemptions

% 

Redemptions (1)

% 

 

(Shares)

Ownership

(Shares)

Ownership

 

DiaCarta Equityholders

 

46,000,000

 

47.1

%  

46,000,000

 

76.3

%

HH&L Class A ordinary shares

 

41,400,000

 

42.3

%  

3,934,298

 

6.5

%

HH&L Class B ordinary shares

 

10,350,000

 

10.6

%  

10,350,000

 

17.1

%

Pro forma common stock outstanding at June 30, 2022

 

97,750,000

100

60,284,298

 

100

%

(1)

Reflects maximum redemptions of 37,465,702 shares owned by public shareholders, assuming SPAC closing cash will meet the minimal threshold under the Sponsor Shares Forfeiture Agreement without any transaction financing.

For further details, see “BCA Proposal—The Merger Agreement—Consideration—Aggregate Merger Consideration.”

Q:

How has the announcement of the Business Combination affected the trading price of the HH&L Class A ordinary shares?

A:

On October 13, 2022, the trading date before the public announcement of the Business Combination, HH&L’s public units, HH&L Class A ordinary shares and public warrants closed at $9.96, $9.95 and $0.03, respectively.

Q:

Will HH&L obtain new financing in connection with the Business Combination?

A:

Pursuant to the Merger Agreement, HH&L has agreed to seek additional investors through one or more private placements acceptable to DiaCarta of shares of common stock of DiaCarta PubCo at $10.00 per share. See “BCA Proposal—Merger

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Agreement.” However, there is no guarantee that HH&L will be able to obtain additional financings in terms satisfactory to the management of HH&L or any additional financing at all.

Q:

Why is HH&L proposing the HH&L Domestication?

A:

Our board of directors believes that there are significant advantages to us that will arise as a result of a change of HH&L’s domicile to Delaware. Further, HH&L Board believes that any direct benefit that the DGCL provides to a corporation also indirectly benefits its stockholders, who are the owners of the corporation. HH&L Board believes that there are several reasons why a registration by way of continuation as a corporation in Delaware is in the best interests of HH&L and its shareholders, including (i) the prominence, predictability and flexibility of the DGCL, (ii) Delaware’s well-established principles of corporate governance and (iii) the increased ability for Delaware corporations to attract and retain qualified directors. Each of the foregoing are discussed in greater detail in the section entitled “Domestication Proposal—Reasons for the HH&L Domestication.”

To effect the HH&L Domestication, HH&L will file a notice of deregistration with the Cayman Islands Registrar of Companies, together with the necessary accompanying documents, and file a certificate of incorporation and a certificate of corporate domestication with the Secretary of State of the State of Delaware, under which HH&L will be domesticated and continue as a Delaware corporation.

The approval of the Domestication Proposal is a condition to the closing of the Merger under the Merger Agreement. The approval of the Domestication Proposal requires a special resolution under the Cayman Constitutional Documents, being the affirmative vote of holders of a majority of at least two-thirds of the ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting. Abstentions and broker non-votes, while considered present for the purposes of establishing a quorum, will not count as votes cast at the extraordinary general meeting.

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Q:

What amendments will be made to the current constitutional documents of HH&L?

A:

The consummation of the Business Combination is conditioned, among other things, on the HH&L Domestication. Accordingly, in addition to voting on the Business Combination, HH&L’s shareholders are also being asked to consider and vote upon a proposal to approve the HH&L Domestication and replace the Cayman Constitutional Documents, in each case, under the Cayman Islands Companies Act, with the Proposed Organizational Documents, in each case, under the DGCL, which differ materially from the Cayman Constitutional Documents in the following respects:

    

Cayman Constitutional Documents

    

Proposed Organizational Documents

Authorized Shares (Advisory Organizational Documents Proposal 5A)

The Cayman Constitutional Documents authorize 555,000,000 shares, divided into 500,000,000 HH&L Class A ordinary shares, 50,000,000 HH&L Class B ordinary shares and 5,000,000 HH&L Preference Shares.

The Proposed Organizational Documents authorize        shares, consisting of        shares of DiaCarta PubCo common stock and        shares of DiaCarta PubCo preferred stock.

See paragraph 5 of the Existing Memorandum.

See Article IV of the Proposed Certificate of Incorporation.

Authorize the Board of Directors to Issue Preferred Shares Without Shareholder Consent (Advisory Organizational Documents Proposal 5B)

The Cayman Constitutional Documents authorize the issuance of 5,000,000 HH&L Preference Shares with such designation, rights and preferences as may be determined from time to time by HH&L Board. Accordingly, HH&L Board is empowered under the Cayman Constitutional Documents, without shareholder approval, to issue preference shares with dividend, liquidation, redemption, voting or other rights which could adversely affect the voting power or other rights of the holders of ordinary shares (except to the extent it may affect the ability of HH&L to carry out a conversion of HH&L Class B ordinary shares on the Closing Date, as contemplated by the Existing Articles).

The Proposed Organizational Documents authorize the Board to issue all or any shares of preferred stock in one or more series and to fix for each such series such voting powers, full or limited, and such designations, preferences and relative, participating, optional or other special rights and such qualifications, limitations or restrictions thereof, as the Board may determine.

See paragraph 5 of the Existing Memorandum and Article 3 of the Existing Articles.

See Article V, subsection B of the Proposed Certificate of Incorporation.

Classified Board (Advisory Organizational Documents Proposal 5C)

The Cayman Constitutional Documents provide that the HH&L Board shall be composed of one class.

The Proposed Organizational Documents provide that the Board be divided into three classes with only one class of directors being elected in each year and each class serving a three-year term.

See Article 28.2 of the Existing Articles.

See Article VII of the Proposed Certificate of Incorporation.

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Cayman Constitutional Documents

    

Proposed Organizational Documents

Removal of Directors (Advisory Organizational Documents Proposal 5D)

The Cayman Constitutional Documents provide that before a Business Combination, holders of Class B ordinary shares may by an Ordinary Resolution remove any director, and that after a Business Combination, shareholders may by an Ordinary Resolution remove any director.

The Proposed Organizational Documents provide that, subject to the special rights of the holders of any series of preferred stock to elect directors, any director may be removed from office at any time, but only for cause and only by the affirmative vote of the holders of at least a majority of the voting power of all of the then outstanding shares of voting stock entitled to vote generally in the election of directors, voting together as a single class.

See Article 31 of the Cayman Constitutional Documents.

See Article VII of the Proposed Certificate of Incorporation.

Adoption of Supermajority Vote Requirement to Amend the Proposed Organizational Documents (Advisory Organizational Documents Proposal 5D)

The Cayman Constitutional Documents provide that amendments to change HH&L’s name, to alter or add to the existing articles or certain sections of the existing memorandum with respect to any objects, powers or other matters specified therein or to reduce its share capital or any capital redemption reserve fund may be made by a special resolution under Cayman Islands law, being the affirmative vote of holders of a majority of at least two-thirds of the HH&L shares represented in person or by proxy and entitled to vote thereon and who vote at a quorate general meeting.

The Proposed Organizational Documents require the affirmative vote of at least two-thirds of the voting power of the outstanding shares to (i) adopt, amend or repeal the Proposed Bylaws, and to (ii) amend, alter, repeal or rescind Articles VII, VIII, IX, X, XI, XII and XIII of the Proposed Certificate of Incorporation.

See Article 18.3 of the Cayman Constitutional Documents.

See Article XIII of the Proposed Certificate of Incorporation and Article X of the Proposed Bylaws.

Company Name (Advisory Organizational Documents Proposal 5D)

The Cayman Constitutional Documents provide that the name of the company is “HH&L Acquisition Co.”

The Proposed Organizational Documents provide that the name of the corporation will be “DiaCarta, Inc.”

See paragraph 1 of the Existing Memorandum.

See Article I of the Proposed Certificate of Incorporation.

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Cayman Constitutional Documents

    

Proposed Organizational Documents

Perpetual Existence (Advisory Organizational Documents Proposal 5D)

The Cayman Constitutional Documents provide that if HH&L does not consummate a business combination (as defined in the Cayman Constitutional Documents) by 24 months from the consummation of the IPO, or such later time as the shareholders may approve in accordance with the Existing Articles, HH&L will cease all operations except for the purposes of winding up and will redeem the public shares and liquidate HH&L’s trust account.

The Proposed Organizational Documents do not include any provisions relating to DiaCarta PubCo’s ongoing existence; the default under the DGCL will make DiaCarta PubCo’s existence perpetual.

See Article 51.7 of the Cayman Constitutional Documents.

Default rule under the DGCL.

Action by Written Consent of Shareholders (Advisory Organizational Documents Proposal 5D)

The Cayman Constitutional Documents permit shareholders to approve amendments to Article 31.1 by unanimous written resolution.

The Proposed Organizational Documents require stockholders to take action at an annual or special meeting and prohibit stockholder action by written consent in lieu of a meeting.

See Article VIII of the Proposed Certificate of Incorporation.

Exclusive Forum (Advisory Organizational Documents Proposal 5D)

The Cayman Constitutional Documents do not contain a provision adopting an exclusive forum for certain shareholder litigation.

The Proposed Organizational Documents adopt Delaware as the exclusive forum for certain stockholder litigation and the federal district courts of the United States for causes of action brought to enforce any liability or duty created by the Securities Act, the Exchange Act, or any other claim for which the federal courts of the United States have exclusive jurisdiction.

See Article XII of the Proposed Certificate of Incorporation.

Takeovers by Interested Stockholders (Advisory Organizational Documents Proposal 5D)

The Cayman Constitutional Documents do not provide restrictions on takeovers of HH&L by a related shareholder following a business combination.

The Proposed Organizational Documents will have DiaCarta PubCo elect not to be governed by Section 203 of the DGCL relating to takeovers by interested stockholders but will provide other similar restrictions regarding takeovers by interested stockholders.

See Article X of the Proposed Certificate of Incorporation.

Provisions Related to Status as Blank Check Company (Advisory Organizational Documents Proposal 5D)

The Cayman Constitutional Documents include various provisions related to HH&L’s status as a blank check company prior to the consummation of a business combination.

The Proposed Organizational Documents do not include such provisions related to HH&L’s status as a blank check company, which no longer will apply upon consummation of the Merger, as HH&L will cease to be a blank check company at such time.

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Q:

How will the HH&L Domestication affect my ordinary shares, warrants and units?

A:

In connection with the HH&L Domestication, (1) each of the then issued and outstanding 10,350,000 HH&L Class B ordinary shares shall, immediately prior to the HH&L Domestication, convert automatically into a HH&L Class A ordinary share (subject to adjustment of the conversion ratio as provided by the terms of the Cayman Constitutional Documents, as applicable) in accordance with and pursuant to the approval to be granted by the shareholders of HH&L (and subject to the approval of the holders of HH&L Class B ordinary shares); (2) immediately following the conversion described in clause (1), each of the then issued and outstanding 51,750,000 HH&L Class A ordinary shares (including those Class A ordinary shares underlying the HH&L units) will convert automatically, on a one-for-one basis, into a share of DiaCarta PubCo common stock; (3) each of the then issued and outstanding 30,980,000 HH&L warrants (including those warrants underlying the HH&L units) will convert automatically into a DiaCarta PubCo warrant pursuant to the Warrant Agreement; and (4) each of the then issued and outstanding units of HH&L that have not been previously separated into the underlying HH&L Class A ordinary shares and underlying HH&L warrants upon the request of the holder thereof, will convert into a unit of DiaCarta PubCo (the “DiaCarta PubCo units”), with each DiaCarta PubCo unit representing one share of DiaCarta PubCo common stock and one-half (1/2) of one DiaCarta PubCo warrant. Upon the closing of the Business Combination, immediately prior to the effective time of the Merger, each issued and outstanding DiaCarta PubCo unit immediately prior to the effective time will be automatically separated and the holder thereof shall be deemed to hold one share of DiaCarta PubCo common stock and one-half (1/2) of one DiaCarta PubCo warrant. No fractional DiaCarta PubCo warrants will be issued upon separation of the DiaCarta PubCo units. See “Domestication Proposal” for additional information.

Q:

What are the material U.S. federal income tax consequences of the HH&L Domestication?

A:

As discussed more fully under “U.S. Federal Income Tax Considerations,” HH&L intends for the HH&L Domestication to qualify as a reorganization within the meaning of Section 368(a)(1)(F) of the U.S. Internal Revenue Code of 1986, as amended (the “Code”). Assuming that the HH&L Domestication so qualifies, and subject to the “passive foreign investment company” (“PFIC”) rules discussed below and under “U.S. Federal Income Tax Considerations—I. U.S. Holders—A. Tax Effects of the HH&L Domestication to U.S. Holders—5. PFIC Considerations,” U.S. Holders (as defined in “U.S. Federal Income Tax Considerations—I. U.S. Holders”) will be subject to Section 367(b) of the Code and, as a result:

A U.S. Holder who beneficially owns (directly, indirectly or constructively) 10% or more of the total combined voting power of all classes of HH&L stock entitled to vote or 10% or more of the total value of all classes of HH&L stock (a “10% U.S. Shareholder”) on the date of the HH&L Domestication must include in income as a dividend deemed paid by HH&L the “all earnings and profits amount” attributable to the HH&L Class A ordinary shares it directly owns within the meaning of Treasury Regulations under Section 367 of the Code. Any U.S. Holder that is a corporation may, under certain circumstances, effectively be exempt from taxation on a portion or all of the deemed dividend pursuant to Section 245A of the Code;
A U.S. Holder whose HH&L Class A ordinary shares have a fair market value of $50,000 or more and who, on the date of the HH&L Domestication, is not a 10% U.S. Shareholder will recognize gain (but not loss) with respect to its HH&L Class A ordinary shares in the HH&L Domestication or, in the alternative, may elect to recognize the “all earnings and profits” amount attributable to such U.S. Holder’s HH&L Class A ordinary shares; and
A U.S. Holder whose HH&L Class A ordinary shares have a fair market value of less than $50,000 on the date of the HH&L Domestication and who, on the date of the HH&L Domestication, is not a 10% U.S. Shareholder, should not be required to recognize any gain or loss or include any part of the “all earnings and profits amount” in income under Section 367 of the Code in connection with the HH&L Domestication.

HH&L does not expect to have significant cumulative earnings and profits, if any, on the date of the HH&L Domestication.

As discussed more fully under “U.S. Federal Income Tax Considerations—I. U.S. Holders—A. Tax Effects of the HH&L Domestication to U.S. Holders—5. PFIC Considerations,” HH&L believes that it is likely classified as a PFIC for U.S. federal income tax purposes. In such case, notwithstanding the U.S. federal income tax consequences of the Domestication discussed in

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the foregoing, proposed Treasury Regulations under Section 1291(f) of the Code (which have a retroactive effective date), if finalized in their current form, generally would require a U.S. Holder to recognize gain on the exchange of HH&L Class A ordinary shares or warrants for DiaCarta PubCo common stock or warrants pursuant to the HH&L Domestication. Any such gain would be taxable income with no corresponding receipt of cash in the HH&L Domestication. The tax on any such gain would be imposed at the rate applicable to ordinary income and an interest charge would apply based on a complex set of rules. In addition, the proposed Treasury Regulations provide coordinating rules with other sections of the Code, including Section 367(b), which affect the manner in which the rules under such other sections apply to transfers of PFIC stock. However, it is difficult to predict whether, in what form, and with what effective date, final Treasury Regulations under Section 1291(f) of the Code may be adopted and how any such Treasury Regulations would apply. Importantly, however, U.S. Holders that make or have made certain elections discussed further under “U.S. Federal Income Tax Considerations—I. U.S. Holders—A. Tax Effects of the HH&L Domestication to U.S. Holders—5. PFIC Considerations—d. QEF Election and Mark-to-Market Election” with respect to their HH&L Class A ordinary shares are generally not subject to the same gain recognition rules under the currently proposed Treasury Regulations under Section 1291(f) of the Code. Currently, there are no elections available that apply to HH&L warrants, and the application of the PFIC rules to HH&L warrants is unclear. For a more complete discussion of the potential application of the PFIC rules to U.S. Holders as a result of the Domestication, see “U.S. Federal Income Tax Considerations—I. U.S. Holders.”

Each U.S. Holder of HH&L Class A ordinary shares or warrants is urged to consult its own tax advisor concerning the application of the PFIC rules, including the proposed Treasury Regulations, to the exchange of HH&L Class A ordinary shares and warrants for DiaCarta PubCo common stock and warrants pursuant to the HH&L Domestication.

Additionally, the HH&L Domestication may cause Non-U.S. Holders (as defined in “U.S. Federal Income Tax Considerations—II. Non-U.S. Holders”) to become subject to U.S. federal income withholding taxes on any amounts treated as dividends paid in respect of such Non-U.S. Holder’s DiaCarta PubCo common stock after the Domestication.

The tax consequences of the HH&L Domestication are complex and will depend on a holder’s particular circumstances. All holders are urged to consult their tax advisor regarding the tax consequences to them of the HH&L Domestication, including the applicability and effect of U.S. federal, state, local and non-U.S. tax laws. For a more complete discussion of the U.S. federal income tax considerations of the HH&L Domestication, see “U.S. Federal Income Tax Considerations.”

Q.

Do I have redemption rights?

A:

If you are a holder of public shares, you have the right to request that we redeem all or a portion of your public shares for cash provided that you follow the procedures and deadlines described elsewhere in this proxy statement / prospectus. Public shareholders may elect to redeem all or a portion of the public shares held by them regardless of if or how they vote in respect of the BCA Proposal. If you wish to exercise your redemption rights, please see the answer to the next question: “How do I exercise my redemption rights?”

Notwithstanding the foregoing, a public shareholder, together with any affiliate of such public shareholder or any other person with whom such public shareholder is acting in concert or as a “group” (as defined in Section 13(d)(3) of the Exchange Act), will be restricted from redeeming its public shares with respect to more than an aggregate of 20% of the public shares. Accordingly, if a public shareholder, alone or acting in concert or as a group, seeks to redeem more than 20% of the public shares, then any such shares in excess of that 20% limit would not be redeemed for cash.

The Sponsor and certain directors and officers of HH&L has agreed to waive its redemption rights with respect to all of the Founder Shares in connection with the consummation of the Business Combination. The Founder Shares will be excluded from the pro rata calculation used to determine the per-share redemption price.

Q:

How do I exercise my redemption rights?

A:

If you are a public shareholder and wish to exercise your right to redeem the public shares, you must:

(i)(a) hold public shares, or (b) if you hold public shares through HH&L units, you elect to separate your HH&L units into the underlying public shares and public warrants prior to exercising your redemption rights with respect to the public shares;

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(ii)submit a written request to Continental, HH&L’s transfer agent, that DiaCarta PubCo redeem all or a portion of your public shares for cash; and
(iii)deliver your certificates for public shares (if any) along with the redemption forms to Continental, HH&L’s transfer agent, physically or electronically through the DTC.

Holders must complete the procedures for electing to redeem their public shares in the manner described above prior to                 , Eastern Time, on                  (two business days before the extraordinary general meeting) in order for their shares to be redeemed.

The address of Continental, HH&L’s transfer agent, is listed under the question “Who can help answer my questions?” below.

Holders of HH&L units must elect to separate the HH&L units into the underlying public shares and public warrants prior to exercising redemption rights with respect to the public shares. If holders hold their HH&L units in an account at a brokerage firm or bank, holders must notify their broker or bank that they elect to separate the HH&L units into the underlying public shares and public warrants, or if a holder holds HH&L units registered in its own name, the holder must contact Continental, HH&L’s transfer agent, directly and instruct them to do so.

Public shareholders will be entitled to request that their public shares be redeemed for a pro rata portion of the amount then on deposit in the trust account calculated as of two business days prior to the consummation of the Business Combination including interest earned on the funds held in the trust account and not previously released to us (net of taxes payable). For illustrative purposes, as of June 30, 2022, this would have amounted to approximately $10.02 per issued public share. However, the proceeds deposited in the trust account could become subject to the claims of HH&L’s creditors, if any, which could have priority over the claims of the public shareholders, regardless of whether such public shareholders vote or, if they do vote, irrespective of if they vote for or against the BCA Proposal. Therefore, the per share distribution from the trust account in such a situation may be less than originally expected due to such claims. Whether you vote, and if you do vote irrespective of how you vote, on any proposal, including the BCA Proposal, will have no impact on the amount you will receive upon exercise of your redemption rights. It is expected that the funds to be distributed to public shareholders electing to redeem their public shares will be distributed promptly after the consummation of the Business Combination.

A HH&L shareholder may not withdraw a redemption request once submitted to HH&L unless HH&L Board determines (in their sole discretion) to permit the withdrawal of such redemption request (which they may do in whole or in part). Furthermore, if a holder of a public share delivers its certificate (if any) along with the redemption forms in connection with an election of its redemption and subsequently decides prior to the applicable date not to elect to exercise such rights, it may simply request that HH&L permit the withdrawal of the redemption request and instruct Continental, HH&L’s transfer agent, to return the certificate (physically or electronically). The holder can make such request by contacting Continental, HH&L’s transfer agent, at the address or email address listed in this proxy statement / prospectus.

Any corrected or changed written exercise of redemption rights must be received by Continental, HH&L’s transfer agent, prior to the vote taken on the BCA Proposal at the extraordinary general meeting. No request for redemption will be honored unless the holder’s certificates for public shares (if any) along with the redemption forms have been delivered (either physically or electronically) to Continental, HH&L’s agent, at least two business days prior to the vote at the extraordinary general meeting.

If a holder of public shares properly makes a request for redemption and the certificates for public shares (if any) along with the redemption forms are delivered as described above, then, if the Business Combination is consummated, DiaCarta PubCo will redeem the public shares for a pro rata portion of funds deposited in the trust account, calculated as of two business days prior to the consummation of the Business Combination. The redemption will take place following the Domestication and, accordingly, it is shares of DiaCarta PubCo common stock that will be redeemed immediately after consummation of the Business Combination.

If you are a holder of public shares and you exercise your redemption rights, such exercise will not result in the loss of any warrants that you may hold.

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Q:

If I am a holder of HH&L units, can I exercise redemption rights with respect to my HH&L units?

A:

No. Holders of issued and outstanding HH&L units must elect to separate the HH&L units into the underlying public shares and public warrants prior to exercising redemption rights with respect to the public shares. If you hold your HH&L units in an account at a brokerage firm or bank, you must notify your broker or bank that you elect to separate the HH&L units into the underlying public shares and public warrants, or if you hold units registered in your own name, you must contact Continental, HH&L’s transfer agent, directly and instruct them to do so. You are requested to cause your public shares to be separated and delivered to Continental, HH&L’s transfer agent, along with the redemption forms by                 , Eastern Time, on                  (two business days before the extraordinary general meeting) in order to exercise your redemption rights with respect to your public shares.

Q:

What are the U.S. federal income tax consequences of exercising my redemption rights?

A:

The U.S. federal income tax consequences of exercising your redemption rights with respect to your HH&L Class A ordinary shares to receive cash from the trust account in exchange for DiaCarta PubCo common stock depend on your particular facts and circumstances. It is possible that you may be treated as selling such DiaCarta PubCo common stock and, as a result, recognize capital gain or capital loss. It is also possible that the redemption may be treated as a distribution for U.S. federal income tax purposes. Whether a redemption of shares of DiaCarta PubCo common stock qualifies for sale treatment will depend largely on the total number of shares of DiaCarta PubCo stock you are treated as owning before and after the redemption (including any DiaCarta PubCo stock that you constructively own as a result of owning DiaCarta PubCo warrants and any DiaCarta PubCo stock that you directly or indirectly acquire pursuant to the Business Combination) relative to all of the DiaCarta PubCo stock outstanding both before and after the redemption. For a more complete discussion of the U.S. federal income tax considerations of an exercise of redemption rights, see “U.S. Federal Income Tax Considerations.”

Additionally, because the Domestication will occur prior to the redemption of any shareholder, U.S. Holders (as defined in “U.S. Federal Income Tax Considerations—I. U.S. Holders”) exercising redemption rights will be subject to the potential tax consequences of Section 367 of the Code as well as potential tax consequences of the U.S. federal income tax rules relating to PFICs. The tax consequences of Section 367 of the Code and the PFIC rules are discussed more fully below under “U.S. Federal Income Tax Considerations—I. U.S. Holders.”

All holders considering exercising redemption rights are urged to consult their tax advisor on the tax consequences to them of an exercise of redemption rights, including the applicability and effect of U.S. federal, state, local and non-U.S. tax laws.

TAX MATTERS ARE COMPLICATED, AND THE TAX CONSEQUENCES OF EXERCISING YOUR REDEMPTION RIGHTS WILL DEPEND ON THE FACTS OF YOUR OWN SITUATION. YOU SHOULD CONSULT YOUR OWN TAX ADVISOR AS TO THE SPECIFIC TAX CONSEQUENCES OF THE EXERCISE OF REDEMPTION RIGHTS TO YOU IN YOUR PARTICULAR CIRCUMSTANCES.

Q:

What happens to the funds deposited in the trust account after consummation of the Business Combination?

A:

Following the closing of HH&L’s initial public offering, an amount equal to $414,000,000  ($10.00 per unit) of the net proceeds from HH&L’s initial public offering and the sale of the private placement warrants was placed in the trust account. As of June 30, 2022, there were $414,645,708 in investments and cash held in the trust account and the Company had approximately $11,000 held outside the trust account. As of June 30, 2022, funds in the trust account totaled $414,645,708 and were comprised entirely of U.S. government treasury bills, notes or bonds with a maturity of 180 days or less or in certain money market funds meeting certain conditions under Rule 2a-7 under the Investment Company Act of 1940, as amended (the “Investment Company Act”), which invest only in direct U.S. government treasury obligations. These funds will remain in the trust account, except for the withdrawal of interest to pay taxes, if any, until the earliest of (1) the completion of a business combination (including the Closing), (2) the redemption of any public shares properly tendered in connection with a shareholder vote to amend the Cayman Constitutional Documents to modify the substance or timing of HH&L’s obligation to redeem 100% of the public shares if it does not complete a business combination by February 9, 2023 (or, if extended, such other deadline by which we are required to consummate a business combination transaction (the “Extended Deadline”)) and (3) the redemption of all of the public shares if HH&L is unable to complete a business combination by February 9, 2023 (or the Extended Deadline), subject to applicable law.

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Upon consummation of the Business Combination, the funds deposited in the trust account will be released to pay holders of HH&L public shares who properly exercise their redemption rights; to pay transaction fees and expenses associated with the Business Combination; and for working capital and general corporate purposes of DiaCarta PubCo following the Business Combination. See “Summary of the Proxy Statement / Prospectus—Sources and Uses of Funds for the Business Combination.”

Q:

What happens if a substantial number of the public shareholders vote in favor of the BCA Proposal and other Condition Precedent Proposals and exercise their redemption rights?

A:

Our public shareholders are not required to vote in respect of the Business Combination in order to exercise their redemption rights. Accordingly, the Business Combination may be consummated even though the funds available from the trust account and the number of public shareholders are reduced as a result of redemptions by public shareholders.

The Merger Agreement provides that the obligations of DiaCarta to consummate the Merger are conditioned on customary closing conditions. If such conditions are not met, and such conditions are not or cannot be waived under the terms of the Merger Agreement, then the Merger Agreement could terminate and the proposed Business Combination may not be consummated. In addition, in no event will HH&L redeem public shares in an amount that would cause its net tangible assets to be less than $5,000,001.

Q:

What conditions must be satisfied to complete the Business Combination?

A:

The Merger Agreement is subject to the satisfaction or waiver of certain customary closing conditions, including, among others, (i) approval of the Business Combination and related agreements and transactions by the respective shareholders of HH&L and DiaCarta, (ii) effectiveness of the registration statement on Form S-4 of which this proxy statement / prospectus forms a part to be filed by HH&L in connection with the Business Combination, (iii) expiration or termination of the waiting period required by the antitrust authorities (as contemplated by the Merger Agreement), (iv) receipt of approval for listing on the NYSE of the shares of DiaCarta PubCo common stock to be issued in connection with the Merger, (v) that after redemption, HH&L’s net tangible assets shall be no less than $5,000,001 upon Closing and (vi) the absence of certain injunctions. We cannot assure you that the parties to the Merger Agreement would waive such conditions.

For more information about conditions to the consummation of the Business Combination, see “BCA Proposal—The Merger Agreement.”

Q:

When do you expect the Business Combination to be completed?

A:

It is currently expected that the Business Combination will be consummated in the first quarter of 2023. This date depends, among other things, on the approval of the proposals to be put to HH&L shareholders at the extraordinary general meeting. However, such meeting could be adjourned if the Adjournment Proposal is adopted by HH&L’s shareholders at the extraordinary general meeting and HH&L elects to adjourn the extraordinary general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies in the event that there are insufficient votes for the approval of one or more proposals at the extraordinary general meeting. For a description of the conditions for the completion of the Business Combination, see “BCA Proposal—The Merger Agreement.”

Q:

What happens if the Business Combination is not consummated?

A:

HH&L will not complete the Domestication to Delaware unless all other conditions to the consummation of the Business Combination have been satisfied or waived by the parties in accordance with the terms of the Merger Agreement. If HH&L is not able to complete the Business Combination with DiaCarta by February 9, 2023 (or the Extended Deadline) and is not able to complete another business combination by such date, in each case, as such date may be extended pursuant to the Cayman Constitutional Documents, HH&L will: (1) cease all operations except for the purpose of winding up; (2) as promptly as reasonably possible, but not more than 10 business days thereafter, redeem the public shares, at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account, including interest (less up to $100,000 of interest to pay dissolution expenses and which interest shall be net of taxes payable), divided by the number of then issued public shares, which redemption will completely extinguish public shareholders’ rights as shareholders (including the right to receive further liquidating distributions, if any), subject to applicable law; and (3) as promptly as reasonably possible following such redemption,

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subject to the approval of our remaining shareholders and our board, dissolve and liquidate, subject in each case to our obligations under Cayman Islands law to provide for claims of creditors and the requirements of other applicable law.

Q:

What do I need to do now?

A:

HH&L urges you to read this proxy statement / prospectus, including the Annexes and the documents referred to herein, carefully and in their entirety and to consider how the Business Combination will affect you as a shareholder or warrant holder. HH&L’s shareholders should then vote as soon as possible in accordance with the instructions provided in this proxy statement / prospectus and on the enclosed proxy card.

Q:

How do I vote?

A:

If you are a holder of record of ordinary shares on the record date for the extraordinary general meeting, you may vote in person at the extraordinary general meeting or by submitting a proxy for the extraordinary general meeting. You may submit your proxy by completing, signing, dating and returning the enclosed proxy card in the accompanying pre-addressed postage-paid envelope. If you hold your shares in “street name,” which means your shares are held of record by a broker, bank or nominee, you should contact your broker, bank or nominee to ensure that votes related to the shares you beneficially own are properly counted. In this regard, you must provide the broker, bank or nominee with instructions on how to vote your shares or, if you wish to attend the extraordinary general meeting and vote in person, obtain a valid proxy from your broker, bank or nominee.

Q:

If my shares are held in “street name,” will my broker, bank or nominee automatically vote my shares for me?

A:

No. If your shares are held in a stock brokerage account or by a bank or other nominee, you are considered the “beneficial holder” of the shares held for you in what is known as “street name.” If this is the case, this proxy statement / prospectus may have been forwarded to you by your brokerage firm, bank or other nominee, or its agent, and you may need to obtain a proxy form from the institution that holds your shares and follow the instructions included on that form regarding how to instruct your broker, bank or nominee as to how to vote your shares. Under the rules of various national and regional securities exchanges, your broker, bank, or nominee cannot vote your shares with respect to non-discretionary matters unless you provide instructions on how to vote in accordance with the information and procedures provided to you by your broker, bank, or nominee. We believe all the proposals presented to the shareholders will be considered non-discretionary and therefore your broker, bank, or nominee cannot vote your shares without your instruction. Your bank, broker, or other nominee can vote your shares only if you provide instructions on how to vote. As the beneficial holder, you have the right to direct your broker, bank or other nominee as to how to vote your shares and you should instruct your broker to vote your shares in accordance with directions you provide. If you do not provide voting instructions to your broker on a particular proposal on which your broker does not have discretionary authority to vote, your shares will not be voted on that proposal. This is called a “broker non-vote.” Abstentions and broker non-votes, while considered present for the purposes of establishing a quorum, will not count as votes cast at the extraordinary general meeting, and otherwise will have no effect on a particular proposal.

Q:

Do I have appraisal rights in connection with the proposed Business Combination and the proposed HH&L Domestication?

A:

Neither HH&L’s shareholders nor HH&L’s warrant holders have appraisal rights in connection with the Business Combination or the HH&L Domestication under Cayman Islands law. HH&L’s shareholders who has voted in favor of the Business Combination and the HH&L Domestication and who is entitled to demand and has exercised appraisal rights of their shares in accordance with Section 262 of the DGCL shall be entitled to such rights as are granted by Section 262 of the DGCL.

Q:

When and where will the extraordinary general meeting be held?

A:

The extraordinary general meeting will be held at                 , Eastern Time, on                 , at the offices of White & Case LLP located at 1221 Avenue of the Americas, New York, NY 10020, or virtually via live webcast at https://www.cstproxy.com/hhlacquisition/2022, or such other date, time and place to which such meeting may be adjourned or postponed, to consider and vote upon the proposals.

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Q:

Who is entitled to vote at the extraordinary general meeting?

A:

HH&L has fixed                  as the record date for the extraordinary general meeting. If you were a shareholder of HH&L at the close of business on the record date, you are entitled to vote on matters that come before the extraordinary general meeting. However, a shareholder may only vote its, his or her shares if it, he or she is present in person or is represented by proxy at the extraordinary general meeting.

Q:

How many votes do I have?

A:

HH&L shareholders are entitled to one vote at the extraordinary general meeting for each ordinary share held of record as of the record date. As of the close of business on the most recent practicable date before the date of this proxy statement / prospectus, there were 51,750,000 ordinary shares issued and outstanding (including those ordinary shares underlying the HH&L units), of which 41,400,000 were issued public shares.

Q:

What constitutes a quorum?

A:

A quorum of HH&L shareholders is necessary to hold a valid meeting. A quorum will be present at the extraordinary general meeting if the holders of a majority of the issued ordinary shares entitled to vote at the extraordinary general meeting are represented in person or by proxy. As of the most recent practicable date before the date of this proxy statement / prospectus, 25,875,001 public shares would be required to achieve a quorum.

Q:

What vote is required to approve each proposal at the extraordinary general meeting?

BCA Proposal: The approval of the BCA Proposal (including the Merger) requires a special resolution under Cayman Islands law, being the affirmative vote of a majority of at least two-thirds the ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting.
Class B Conversion Proposal: The approval of the Class B Conversion Proposal requires a special resolution under the Cayman Constitutional Documents, being the affirmative vote of holders of a majority of at least two-thirds of the ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting.
Domestication Proposal: The approval of the Domestication Proposal requires a special resolution under the Cayman Constitutional Documents, being the affirmative vote of holders of a majority of at least two-thirds of the ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting.
Organizational Documents Proposal: The approval of the Organizational Documents Proposal (including the amendment of the Cayman Constitutional Documents) requires a special resolution under the Cayman Islands Companies Act, being the affirmative vote of holders of a majority of at least two-thirds of the ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting.
Advisory Organizational Documents Proposals: The separate approval of each of the Advisory Organizational Documents Proposals, each of which is a non-binding vote, requires a special resolution under the Cayman Islands Companies Act, being the affirmative vote of holders of a majority of at least two-thirds of the ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting.
Director Election Proposal: The approval of the Director Election Proposal requires an ordinary resolution under the Cayman Constitutional Documents, being the affirmative vote of holders of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon and who voted at the quorate extraordinary general meeting. Under the terms of the Cayman Constitutional Documents, only the holders of HH&L Class B ordinary shares are entitled to vote on the election of directors to the HH&L Board. Therefore, only holders of the HH&L Class B ordinary shares will vote on the election of

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directors at the quorate extraordinary general meeting. Neither the failure to vote or abstentions by holders of HH&L Class A ordinary shares will have any effect on the outcome of the proposal.
Stock Issuance Proposal: The Stock Issuance Proposal is being proposed for approval by way of ordinary resolution, being the affirmative vote of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting.
Equity Incentive Plan Proposal: The Equity Incentive Plan Proposal is being proposed for approval by way of ordinary resolution, being the affirmative vote of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting.
Adjournment Proposal: The Adjournment Proposal is being proposed for approval by way of ordinary resolution, being the affirmative vote of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon and who vote at the quorate extraordinary general meeting.

Q:

What are the recommendations of HH&L Board?

A:

HH&L Board believes that the BCA Proposal and the other proposals to be presented at the extraordinary general meeting are in the best interests of HH&L’s shareholders and unanimously recommends that its shareholders vote “FOR” the approval of the BCA Proposal, “FOR” the approval of the Class B Conversion Proposal, “FOR” the approval of the Domestication Proposal, “FOR” the approval of the Organizational Documents Proposal, “FOR” the approval of each of the separate Advisory Organizational Documents Proposals, “FOR” the approval of the Director Election Proposal, “FOR” the approval of the Stock Issuance Proposal, “FOR” the approval of the Equity Incentive Plan Proposal, and “FOR” the approval of the Adjournment Proposal, in each case, if presented to the extraordinary general meeting.

The existence of financial and personal interests of one or more of HH&L’s directors may result in a conflict of interest on the part of such director(s) between what he, she or they may believe is in the best interests of HH&L and its shareholders and what he, she or they may believe is best for himself, herself or themselves in determining to recommend that shareholders vote for the proposals. In addition, HH&L’s officers have interests in the Business Combination that may conflict with your interests as a shareholder. See “BCA Proposal—Interests of HH&L’s Directors and Executive Officers in the Business Combination” for a further discussion of these considerations.

Q:

How does the Sponsor intend to vote its shares?

A:

The Sponsor has agreed to vote all the founder shares and any other public shares it may hold in favor of all the proposals being presented at the extraordinary general meeting. As of the date of this proxy statement / prospectus, the Sponsor (whose members include HH&L’s directors and officers) owns 20% of the issued and outstanding ordinary shares.

At any time at or prior to the Business Combination, subject to applicable securities laws (including with respect to material non-public information), the Sponsor, the existing shareholders of DiaCarta or our or their respective directors, officers, advisors or respective affiliates may (i) purchase public shares from institutional and other investors who vote, or indicate an intention to vote, against any of the Condition Precedent Proposals, or elect to redeem, or indicate an intention to redeem, public shares, (ii) execute agreements to purchase such shares from such investors in the future, or (iii) enter into transactions with such investors and others to provide them with incentives to acquire public shares, vote their public shares in favor of the Condition Precedent Proposals or not redeem their public shares. Such a purchase may include a contractual acknowledgement that such shareholder, although still the record holder of HH&L’s shares, is no longer the beneficial owner thereof and therefore agrees not to exercise its redemption rights. In the event that the Sponsor, the existing shareholders of DiaCarta or our or their respective directors, officers, advisors, or respective affiliates purchase shares in privately negotiated transactions from public shareholders who have already elected to exercise their redemption rights, such selling shareholders would be required to revoke their prior elections to redeem their shares. The purpose of such share purchases and other transactions would be to increase the likelihood of (1) satisfaction of the requirement that holders of a majority of the ordinary shares, represented in person or by proxy and entitled to vote at the extraordinary general meeting, vote in favor of the Director Election Proposal, the Stock Issuance Proposal, the Equity Incentive Plan Proposal and the Adjournment Proposal, (2) satisfaction of the requirement that holders of a majority of

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at least two-thirds of the ordinary shares, represented in person or by proxy and entitled to vote at the extraordinary general meeting, vote in favor of the BCA Proposal, the Class B Conversion Proposal, the Domestication Proposal, the Organizational Documents Proposal, and the Advisory Organizational Documents Proposals, (3)  otherwise limiting the number of public shares electing to redeem and (4) HH&L’s net tangible assets being at least $5,000,001.

Entering into any such arrangements may have a depressive effect on our ordinary shares (e.g., by giving an investor or holder the ability to effectively purchase shares at a price lower than market, such investor or holder may therefore become more likely to sell the shares it, he or she owns, either at or prior to the Business Combination). If such transactions are effected, the consequence could be to cause the Business Combination to be consummated in circumstances where such consummation could not otherwise occur. Purchases of shares by the persons described above would allow them to exert more influence over the approval of the proposals to be presented at the extraordinary general meeting and would likely increase the chances that such proposals would be approved.

The existence of financial and personal interests of one or more of HH&L’s directors may result in a conflict of interest on the part of such director(s) between what he, she or they may believe is in the best interests of HH&L and its shareholders and what he, she or they may believe is best for himself, herself or themselves in determining to recommend that shareholders vote for the proposals. In addition, HH&L’s officers have interests in the Business Combination that may conflict with your interests as a shareholder. See “BCA Proposal—Interests of HH&L’s Directors and Executive Officers in the Business Combination” for a further discussion of these considerations.

Q:

What happens if I sell my HH&L ordinary shares before the extraordinary general meeting?

A:

The record date for the extraordinary general meeting is earlier than the date of the extraordinary general meeting and earlier than the date that the Business Combination is expected to be completed. If you transfer your public shares after the applicable record date, but before the extraordinary general meeting, unless you grant a proxy to the transferee, you will retain your right to vote at such general meeting but the transferee, and not you, will have the ability to redeem such shares (if time permits), so long as such transferee takes the required steps to elect to redeem such shares at least two business days prior to the extraordinary general meeting.

Q:

May I change my vote after I have mailed my signed proxy card?

A:

Yes. Shareholders may send a later-dated, signed proxy card to HH&L’s Chief Executive Officer and Director at HH&L’s address set forth below so that it is received by HH&L’s Chief Executive Officer and Director prior to the vote at the extraordinary general meeting (which is scheduled to take place on                 ) or attend the extraordinary general meeting in person and vote. Shareholders also may revoke their proxy by sending a notice of revocation to HH&L’s Chief Executive Officer and Director, which must be received by HH&L’s Chief Executive Officer and Director prior to the vote at the extraordinary general meeting. However, if your shares are held in “street name” by your broker, bank or another nominee, you must contact your broker, bank or other nominee to change your vote.

Q:

What happens if I fail to take any action with respect to the extraordinary general meeting?

A:

If you fail to take any action with respect to the extraordinary general meeting and the Business Combination is approved by shareholders and the Business Combination is consummated, you will become a stockholder or warrant holder of DiaCarta PubCo. If you fail to take any action with respect to the extraordinary general meeting and the Business Combination is not approved, you will remain a shareholder or warrant holder of HH&L. However, if you fail to vote with respect to the extraordinary general meeting, you will nonetheless be able to elect to redeem your public shares in connection with the Business Combination (if time permits).

Q:

How can I vote my shares without attending the extraordinary general meeting?

A:

If you are a shareholder of record of our HH&L shares as of the close of business on the Record Date, you can vote by proxy by mail by following the instructions provided in the enclosed proxy card or at the extraordinary general meeting. Please note that if you are a beneficial owner of HH&L shares, you may vote by submitting voting instructions to your broker, bank or nominee, or

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otherwise by following instructions provided by your broker, bank or nominee. Telephone and internet voting will be available to beneficial owners. Please refer to the vote instruction form provided by your broker, bank or nominee.

Q:

What happens if I vote against the BCA Proposal?

A:

If you vote against the BCA Proposal, but the BCA Proposal still obtains the requisite shareholder approval described in this proxy statement / prospectus, then the BCA Proposal will be approved and, assuming the approval of the Class B Conversion Proposal, the Domestication Proposal, the Organizational Documents Proposal, the Advisory Organizational Documents Proposal, the Director Election Proposal, the Stock Issuance Proposal, the Equity Incentive Plan Proposal and the Adjournment Proposal and the satisfaction or waiver of the other conditions to the closing of the Merger, the Business Combination will be consummated in accordance with the terms of the Merger Agreement.

If you vote against the BCA Proposal and the BCA Proposal does not obtain the requisite vote at the extraordinary general meeting, then the BCA Proposal will fail and we will not consummate the Business Combination. If we do not consummate the Business Combination, we may continue to try to complete a business combination with a different target business until February 9, 2023 (or the Extended Deadline). If we fail to complete an initial business combination by February 9, 2023 (or the Extended Deadline), then we will be required to dissolve and liquidate the trust account by returning then-remaining funds in the trust account to the public shareholders.

Q:

What should I do with my share certificates, warrant certificates or unit certificates?

A:

Our shareholders who exercise their redemption rights must deliver (either physically or electronically) their share certificates (if any) along with the redemption forms to Continental, HH&L’s transfer agent, prior to the extraordinary general meeting.

Holders must complete the procedures for electing to redeem their public shares in the manner described above prior to                 , Eastern Time, on                  (two business days before the extraordinary general meeting) in order for their shares to be redeemed.

Our warrant holders should not submit the certificates relating to their warrants. Public shareholders who do not elect to have their public shares redeemed for the pro rata share of the trust account should not submit the certificates relating to their public shares.

Upon the HH&L Domestication and, holders of HH&L units, HH&L Class A ordinary shares, HH&L Class B ordinary shares and warrants will receive shares of DiaCarta PubCo common stock and warrants, as the case may be, without needing to take any action and, accordingly, such holders should not submit any certificates relating to their units, HH&L Class A ordinary shares (unless such holder elects to redeem the public shares in accordance with the procedures set forth above), HH&L Class B ordinary shares or warrants.

Q:

What should I do if I receive more than one set of voting materials?

A:

Shareholders may receive more than one set of voting materials, including multiple copies of this proxy statement / prospectus and multiple proxy cards or voting instruction cards. For example, if you hold your shares in more than one brokerage account, you will receive a separate voting instruction card for each brokerage account in which you hold shares. If you are a holder of record and your shares are registered in more than one name, you will receive more than one proxy card. Please complete, sign, date and return each proxy card and voting instruction card that you receive in order to cast a vote with respect to all of your ordinary shares.

Q:

Who will solicit and pay the cost of soliciting proxies for the extraordinary general meeting?

A:

HH&L will pay the cost of soliciting proxies for the extraordinary general meeting. HH&L has engaged Morrow Sodali to assist in the solicitation of proxies for the extraordinary general meeting. HH&L has agreed to pay Morrow Sodali a fee of $37,500, plus disbursements. HH&L will also reimburse banks, brokers and other custodians, nominees and fiduciaries representing beneficial owners of HH&L Class A ordinary shares for their expenses in forwarding soliciting materials to beneficial owners of HH&L Class A ordinary shares and in obtaining voting instructions from those owners. HH&L’s directors and officers may also

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solicit proxies by telephone, by facsimile, by mail, on the Internet or in person. They will not be paid any additional amounts for soliciting proxies.

Q:

Where can I find the voting results of the extraordinary general meeting?

A:

The preliminary voting results will be expected to be announced at the extraordinary general meeting. HH&L will publish final voting results of the extraordinary general meeting in a Current Report on Form 8-K within four business days after the extraordinary general meeting.

Q:

Who can help answer my questions?

A:

If you have questions about the Business Combination or if you need additional copies of the proxy statement / prospectus or the enclosed proxy card, you should contact:

Morrow Sodali LLC

333 Ludlow Street, 5th Floor, South Tower

Stamford, CT 06902

Telephone: (800) 662-5200

(Banks and brokers can call: (203) 658-9400

Email: HHIA.info@investor.morrowsodali.com

You also may obtain additional information about HH&L from documents filed with the SEC by following the instructions in the section entitled “Where You Can Find More Information.” If you are a holder of public shares and you intend to seek redemption of your public shares, you will need to deliver the certificates for your public shares (if any) along with the redemption forms (either physically or electronically) to Continental, HH&L’s transfer agent, at the address below prior to the extraordinary general meeting. Holders must complete the procedures for electing to redeem their public shares in the manner described above prior to                 , Eastern Time, on                  (two business days before the extraordinary general meeting) in order for their shares to be redeemed. If you have questions regarding the certification of your position or delivery of your share certificates (if any) along with the redemption forms, please contact:

Continental Stock Transfer & Trust Company

1 State Street, 30th Floor

New York, New York 10004

Attention: Mark Zimkind

Email: mzimkind@continentalstock.com

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Summary of the Proxy Statement / Prospectus

This summary highlights selected information from this proxy statement / prospectus and does not contain all of the information that is important to you. To better understand the Proposals to be submitted for a vote at the extraordinary general meeting, including the Business Combination, whether or not you plan to attend such meeting, you should read this entire document carefully, including the Merger Agreement, which is attached as Annex A to this proxy statement / prospectus. The Merger Agreement is the legal document that governs the Business Combination and the other transactions that will be undertaken in connection therewith. The Merger Agreement is also described in detail in this proxy statement / prospectus in the section entitled “BCA Proposal—The Merger Agreement.” You should also read the section entitled “Risk Factors” beginning on page 61 of this proxy statement / prospectus and the section entitled “Where You Can Find More Information” beginning on page 358 of this proxy statement / prospectus.

The Parties to the Business Combination

HH&L

HH&L is a blank check company incorporated on September 4, 2020 as a Cayman Islands exempted company incorporated with limited liability for the purpose of effecting a merger, share exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses.

On February 9, 2021, HH&L consummated its initial public offering of 41,400,000 units, including 5,400,000 units issued pursuant to the exercise in full of the underwriters’ over-allotment option, with each unit consisting of one HH&L Class A ordinary share and one-half (1/2) of one HH&L warrant. The units were sold at a price of $10.00 per unit, generating gross proceeds to HH&L of $414,000,000. Each warrant entitles the holder to purchase one HH&L Class A ordinary share at a price of $11.50 per HH&L Class A ordinary share, subject to adjustment. Concurrently with the closing of the initial public offering, the Sponsor purchased an aggregate of 10,280,000 warrants at a price of $1.00 per warrant, generating gross proceeds to HH&L of $10,280,000.

Following the closing of HH&L’s initial public offering, a total of $414 million ($10.00 per unit) of the proceeds from its initial public offering and the sale of the private placement warrants was placed in the trust account. As of June 30, 2022, there were $414,645,708 in investments and cash held in the trust account and the Company had approximately $11,000 in cash held outside the trust account. As of June 30, 2022, $0 of the funds had been withdrawn from the trust account to fund HH&L’s working capital expenses.

The HH&L units, HH&L Class A ordinary shares and public warrants are currently listed on the NYSE under the symbols “HHLA.U,” “HHLA” and “HHLA WS,” respectively.

HH&L’s principal executive office is located at Suite 2001-2002, 20/F, York House, The Landmark, 15 Queen’s Road Central, Central Hong Kong. Its telephone number is +852 3752 2870. HH&L’s corporate website address is http://www.hopuhl.com. HH&L’s website and the information contained on, or that can be accessed through, the website is not deemed to be incorporated by reference in, and is not considered part of, this proxy statement / prospectus.

Merger Sub

Diamond Merger Sub Inc. (“Merger Sub”) is a Delaware corporation and a wholly owned subsidiary of HH&L. Merger Sub does not own any material assets or operate any business. Merger Sub’s principal executive office is located at Suite 2001-2002, 20/F, York House, The Landmark, 15 Queen’s Road Central, Central Hong Kong. Its telephone number is +852 3752 2870.

DiaCarta

DiaCarta is a leading translational genomics and personalized diagnostics company working to discover, develop, and commercialize highly sensitive precision medicine and molecular diagnostics technologies to address unmet clinical needs. By its proprietary combining XNA and SuperbDNA technologies with a holistic view of the patient’s disease state, DiaCarta believes that its solutions provide physicians with greater insight and scope for personalized patient care while also meaningfully improving disease detection, evaluation, and treatment. DiaCarta’s unique and scalable technology has delivered revenue-generating products in both cancer and infectious disease testing and a robust product pipeline. DiaCarta is a Cayman Islands exempted company incorporated

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with limited liability on 23 October, 2014. Its registered office is situated at Vistra (Cayman) Limited, P.O. Box 31119 Grand Pavilion, Hibiscus Way, 802 West Bay Road, Grand Cayman, KY1-1205, Cayman Islands.

Proposals to be Put to the Shareholders of HH&L at the Extraordinary General Meeting

The following is a summary of the proposals to be put to the extraordinary general meeting of HH&L and certain transactions contemplated by the Merger Agreement. Each of the proposals below, except the Adjournment Proposal, is cross-conditioned on the approval of each other. The Adjournment Proposal is not conditioned upon the approval of any other proposal set forth in this proxy statement / prospectus. The transactions contemplated by the Merger Agreement will be consummated only if the Condition Precedent Proposals are approved at the extraordinary general meeting.

BCA Proposal

As discussed in this proxy statement / prospectus, HH&L is asking its shareholders to approve by special resolution and adopt the Merger Agreement, dated as of October 14, 2022, by and among HH&L, Merger Sub and DiaCarta, a copy of which is attached to this proxy statement / prospectus as Annex A. The Merger Agreement provides for, among other things, following the domestication of HH&L to Delaware as described below and the domestication of DiaCarta to Delaware as described below, the merger of Merger Sub with and into Domesticated DiaCarta, with Domesticated DiaCarta surviving the merger as a wholly owned subsidiary of DiaCarta PubCo, in accordance with the terms and subject to the conditions of the Merger Agreement as more fully described elsewhere in this proxy statement / prospectus. After consideration of the factors identified and discussed in the section entitled “BCA Proposal—HH&L Board’s Reasons for the Approval of the Business Combination,” HH&L Board concluded that the Business Combination met the requirements disclosed in the prospectus for HH&L’s initial public offering, including that the business of DiaCarta and its subsidiaries had a fair market value equal to at least 80% of the net assets held in the trust account (excluding the amount of any deferred underwriting discount held in trust) at the time of HH&L’s signing the Merger Agreement. For more information about the transactions contemplated by the Merger Agreement, see “BCA Proposal.”

Aggregate Merger Consideration

The Aggregate Merger Consideration means a number of shares of DiaCarta PubCo common stock equal to the quotient obtained by dividing (i) the base purchase price of $460,000,000, by (ii) $10.00 (the “Aggregate Merger Consideration”). HH&L has agreed, pursuant to the Merger Agreement, to seek additional investors through one or more private placements of DiaCarta PubCo common stock at $10 per share. The proceeds of such private placement transactions, if any, together with the amounts remaining in HH&L’s trust account as of immediately following the effective time of the Merger, will be retained by DiaCarta PubCo following the Closing. For further details, see “BCA Proposal—The Merger Agreement—Consideration—Aggregate Merger Consideration.”

Closing Conditions

The Merger Agreement is subject to the satisfaction or waiver of certain customary closing conditions, including, among others, (i) approval of the Business Combination and related agreements and transactions by the respective shareholders of HH&L and DiaCarta, (ii) effectiveness of the registration statement on Form S-4 of which this proxy statement / prospectus forms a part to be filed by HH&L in connection with the Business Combination, (iii) expiration or termination of the waiting period required by the antitrust authorities (as contemplated by the Merger Agreement), (iv) receipt of approval for listing on the NYSE of the shares of DiaCarta PubCo common stock to be issued in connection with the Merger, (v) that after redemption, HH&L’s net tangible assets shall be no less than $5,000,001 upon Closing and (vi) the absence of certain injunctions. For further details, see “BCA Proposal—The Merger Agreement.

Class B Conversion Proposal

If the BCA Proposal is approved, HH&L will ask its shareholders to approve the Class B Conversion Proposal in connection with the HH&L Domestication. As the Cayman Constitutional Documents do not provide for automatic conversion of the HH&L Class B ordinary shares in connection with the HH&L Domestication, the Class B Conversion Proposal, if approved, will authorize all issued and outstanding HH&L Class B ordinary shares to be converted into HH&L Class A ordinary shares immediately prior to the effective time of the HH&L Domestication. Approval of the Class B Conversion Proposal is a condition to the consummation of the Business Combination.

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For additional information, see “The Class B Conversion Proposal” beginning on page 187 of this proxy statement / prospectus.

Domestication Proposal

If the BCA Proposal and the Class B Conversion Proposal are approved, HH&L will ask its shareholders to approve the Domestication Proposal in connection with the HH&L Domestication. As a condition to closing the Business Combination pursuant to the terms of the Merger Agreement, the HH&L Board has unanimously approved the Domestication Proposal. The Domestication Proposal, if approved, will authorize a change of HH&L’s jurisdiction of incorporation from the Cayman Islands to the State of Delaware. Accordingly, while HH&L is currently governed by the Cayman Islands Companies Act, upon the HH&L Domestication, DiaCarta PubCo will be governed by the DGCL. There are differences between Cayman Islands Companies Act and DGCL as well as the Cayman Constitutional Documents and the Proposed Organizational Documents. Accordingly, HH&L encourages shareholders to carefully review the information in “Comparison of Corporate Governance and Shareholder Rights” beginning on page 344 of this proxy statement / prospectus.

In connection with the HH&L Domestication, (1) each of the then issued and outstanding 10,350,000 HH&L Class B ordinary shares shall, immediately prior to the HH&L Domestication, convert automatically into a HH&L Class A ordinary share (subject to adjustment of the conversion ratio as provided by the terms of the Cayman Constitutional Documents, as applicable) in accordance with and pursuant to the approval to be granted by the shareholders of HH&L (and subject to the approval of the holders of HH&L Class B ordinary shares); (2) immediately following the conversion described in clause (1), each of the then issued and outstanding 51,750,000 HH&L Class A ordinary shares (including those Class A ordinary shares underlying the HH&L units) will convert automatically, on a one-for-one basis, into a share of DiaCarta PubCo common stock; (3) each of the then issued and outstanding 30,980,000 HH&L warrants (including those warrants underlying the HH&L units) will convert automatically into a DiaCarta PubCo warrant pursuant to the Warrant Agreement; and (4) each HH&L unit will convert into a unit of DiaCarta PubCo (the “DiaCarta PubCo units”), with each DiaCarta PubCo unit representing one share of DiaCarta PubCo common stock and one-half (1/2) of one DiaCarta PubCo warrant. Upon the closing of the Business Combination, immediately prior to the effective time of the Merger, each issued and outstanding DiaCarta PubCo unit immediately prior to the effective time will be automatically separated and the holder thereof shall be deemed to hold one share of DiaCarta PubCo common stock and one-half (1/2) of one DiaCarta PubCo warrant. No fractional DiaCarta PubCo warrants will be issued upon separation of the DiaCarta PubCo units.

For further details, see “Domestication Proposal” beginning on page 188 of this proxy statement / prospectus.

Organizational Documents Proposal

If the BCA Proposal, the Class B Conversion Proposal and the Domestication Proposal are approved, HH&L will ask its shareholders to approve the Organizational Documents Proposal in connection with the replacement of the Cayman Constitutional Documents, under the Cayman Islands Companies Act, with the Proposed Organizational Documents, under the DGCL. HH&L Board has unanimously approved the Organizational Documents Proposal and believes such proposal is necessary to adequately address the needs of DiaCarta PubCo after the Business Combination. Approval of the Organizational Documents Proposal is a condition to the consummation of the Business Combination.

For additional information, see “The Organization Documents Proposal” beginning on page 195 of this proxy statement / prospectus.

Advisory Organizational Documents Proposals

If the BCA Proposal, the Class B Conversion Proposal, the Domestication Proposal and the Organizational Documents Proposal are approved, HH&L will ask its shareholders to approve four separate Advisory Organizational Documents Proposals in connection with the replacement of the Cayman Constitutional Documents, under the Cayman Islands Companies Act, with the Proposed Organizational Documents, under the DGCL. HH&L Board has unanimously approved the Advisory Organizational Documents Proposals and believes such proposals are necessary to adequately address the needs of DiaCarta PubCo after the Business Combination. Approval of the Advisory Organizational Documents Proposals is a condition to the consummation of the Business Combination.

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A brief summary of each of the Advisory Organizational Documents Proposals is set forth below. These summaries are qualified in their entirety by reference to the complete text of the Proposed Organizational Documents.

(A)Advisory Organizational Documents Proposal 5A—to authorize the change in the authorized share capital of HH&L from (i) 500,000,000 HH&L Class A ordinary shares, 50,000,000 HH&L Class B ordinary shares and 5,000,000 HH&L preference shares to (ii)      shares of DiaCarta PubCo common stock and       shares of DiaCarta PubCo preferred stock;
(B)Advisory Organizational Documents Proposal 5B—to authorize the HH&L Board to issue any or all shares of DiaCarta PubCo preferred stock in one or more classes or series, with such terms and conditions as may be expressly determined by DiaCarta PubCo’s board of directors and as may be permitted by the DGCL;
(C)Advisory Organizational Documents Proposal 5C—to provide that DiaCarta PubCo’s board of directors be divided into three classes with only one class of directors being elected in each year and each class serving a three-year term; and
(D)Advisory Organizational Documents Proposal 5D—to authorize all other changes in connection with the replacement of Cayman Constitutional Documents with the Proposed Certificate of Incorporation and Proposed Bylaws in connection with the consummation of the Business Combination (copies of which are attached to this proxy statement / prospectus as Annex H and Annex G, respectively), including (1) changing the company name from “HH&L Acquisition Co.” to “DiaCarta, Inc.,” (2) making DiaCarta PubCo’s corporate existence perpetual, (3) adopting Delaware as the exclusive forum for certain stockholder litigation, (4) electing not to be governed by Section 203 of the DGCL and, instead, be governed by a provision substantially similar to Section 203 of the DGCL, (5) removing certain provisions related to HH&L’s status as a blank check company that will no longer be applicable upon consummation of the Business Combination, (6) requiring stockholders to take action at an annual or special meeting and prohibiting stockholder action by written consent in lieu of a meeting, (7) removing any provisions relating to the removal of DiaCarta PubCo’s directors, and (8) requiring the affirmative vote of at least two-thirds of the voting power of the outstanding shares to (i) adopt, amend or repeal the Proposed Bylaws, and to (ii) amend, alter, repeal or rescind Articles VII, VIII, IX, X, XI, XII and XIII of the Proposed Certificate of Incorporation, all of which HH&L Board believes is necessary to adequately address the needs of DiaCarta PubCo after the Business Combination.

The Proposed Organizational Documents differ in certain material respects from the Cayman Constitutional Documents and HH&L encourages shareholders to carefully review the information set out in the section entitled “Advisory Organizational Documents Proposals” beginning on page 197 of this proxy statement / prospectus and the full text of the Proposed Organizational Documents of DiaCarta PubCo.

Director Election Proposal

Assuming the BCA Proposal, the Class B Conversion Proposal, the Domestication Proposal, the Organizational Documents Proposal and the Advisory Organizational Documents Proposal are approved, HH&L’s shareholder are also being asked to approve by ordinary resolution the Director Election Proposal for purposes of the election of directors to serve on the board of directors of DiaCarta PubCo upon the consummation of the Business Combination. For additional information, see “Director Election Proposal” beginning on page 208 of this proxy statement / prospectus.

Stock Issuance Proposal

Assuming the BCA Proposal, the Class B Conversion Proposal, the Domestication Proposal, the Organizational Documents Proposal, the Advisory Organizational Documents Proposal and the Director Election Proposal are approved, HH&L’s shareholders are also being asked to approve by ordinary resolution the Stock Issuance Proposal for purposes of complying with the applicable provisions of NYSE Listing Rule 312.03, the issuance of shares of DiaCarta PubCo common stock in connection with the Business Combination. For additional information, see “Stock Issuance Proposal” beginning on page 210 of this proxy statement / prospectus.

Equity Incentive Plan Proposal

Assuming the BCA Proposal, the Class B Conversion Proposal, the Domestication Proposal, the Organizational Documents Proposal, the Advisory Organizational Documents Proposal, the Director Election Proposal and the Stock Issuance Proposal are

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approved, HH&L’s shareholders are also being asked to approve by ordinary resolution the 2022 Plan. For additional information, see “Equity Incentive Plan Proposal” beginning on page 212 of this proxy statement / prospectus.

Adjournment Proposal

If, based on the tabulated vote, there are not sufficient votes at the time of the extraordinary general meeting to authorize HH&L to consummate the Business Combination (because any of the Condition Precedent Proposals have not been approved (including as a result of the failure of any other cross-conditioned Condition Precedent Proposals to be approved)), HH&L Board may submit a proposal to adjourn the extraordinary general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies. For additional information, see “Adjournment Proposal” beginning on page 218 of this proxy statement / prospectus.

HH&L Board’s Reasons for the Approval of the Business Combination

In considering the Business Combination, HH&L Board considered multiple positive factors including the following, although not weighted or in any order of significance:

Target with unique and scalable technologies, which has a large addressable market. HH&L Board considered that DiaCarta develops its products based on its proprietary technology platforms, including (i) its XNA technology, which provides a high level of sensitivity as it clamps the wild-type sequence and amplifies the mutant target sequence; and (ii) its SuperbDNA technology that provides a high level of sensitivity in detecting target DNA or RNA by amplifying the signal and does not require extraction or amplification of target DNA or RNA. Based on the XNA technology, DiaCarta has developed its ColoScape colorectal cancer blood test. Based on the SuperbDNA technology, DiaCarta developed its revolutionary RadTox® cfDNA tests, which serves to assess tumor response and enhance patient care in connection with chemotherapy. Together with DiaCarta’s FDA EUA approved QuantiVirus™ SARS-CoV-2 Tests, HH&L Board believed that DiaCarta’s current technologies provide meaningful solutions in the sizeable precision oncology and infectious diseases diagnosis markets.
Strong R&D capability and product pipeline. DiaCarta has strong R&D capabilities backed by its knowledgeable leadership team, partnership with leading healthcare institutions and an experienced scientific advisory board: (i) DiaCarta is led by experienced scientists with doctoral or medical doctor qualifications and significant expertise, and many of them have significant academic accomplishments in diagnostic or related fields and experience accumulated from their prior roles with other prominent healthcare companies; (ii) DiaCarta has engaged in strategic collaborations with leading healthcare institutions in the development and clinical trials of its products; and (iii) DiaCarta has assembled a strong scientific advisory board with accomplished scholars in highly relevant fields, including oncology and immunogenic and molecular diagnostics. Powered by its R&D capabilities, DiaCarta has assembled a strong product pipeline, including monkey pox testing kits, gastric cancer monitoring test, and early screen test for bladder cancer and lung cancer.
Financial Performance. Based on its review of DiaCarta’s historical financial information, the HH&L Board considered that (i) DiaCarta’s management has delivered significant aggregate revenue growth since DiaCarta’s inception, through mixed revenue sources, and has generated net profit in 2021, but also that (ii) a significant portion of DiaCarta’s historical revenue was, and its near-term revenue will likely be, generated from its COVID-19 testing services, the demand for which may be substantially reduced with the production and widely administered use of an efficacious vaccine or treatment for COVID-19.
Experienced and Committed Management Team. The HH&L Board considered that DiaCarta’s management team has extensive experience in business management, healthcare and life science: (i) Mr. Aiguo (Adam) Zhang, the founder, president and chief executive officer of DiaCarta who will be serving as the chairman and chief executive officer of the combined company after closing of the Business Combination, has extensive experience in the life science sector; and (ii) DiaCarta has been led by a strong team of senior management with diversified and complementary skillsets and expertise to support its growth, and such management team will continue to manage the combined company and drive its business growth after closing of the Merger.

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Continued Support by Existing Shareholders.   The HH&L Board noted that (i) existing DiaCarta’s shareholders would not be receiving any cash consideration in connection with the Merger; (ii) existing DiaCarta’s shareholders will continue to own over 40% of the combined company on a fully-diluted basis immediately after the Closing (assuming no redemptions by HH&L public shareholders); and (iii) major shareholders of DiaCarta agreed to have their ownership subjected to post-closing lock-up arrangements, such that, subject to limited exceptions, as of the date of this proxy statement / prospectus, shareholders representing over two-thirds of DiaCarta’s issued and outstanding shares have agreed to a 12-month lock-up of the shares of DiaCarta PubCo common stock to be acquired by them at closing of the Merger. The HH&L Board considered these to be strong signs of DiaCarta’s existing shareholders confidence in the combined company and the benefits to be realized as a result of the Merger.
Terms of the Merger Agreement. The HH&L Board determined that the terms and conditions of the Merger Agreement were fair, advisable and in the best interests of HH&L and HH&L’s shareholders and were the product of arm’s-length negotiations among the parties.
Due Diligence. The HH&L Board considered the fact that HH&L has conducted extensive due diligence review of, among others, DiaCarta’s business, industry dynamics, financial results, material contracts and regulatory compliance, and held discussions with DiaCarta’s management and financial and legal advisors.
Other Alternatives. The HH&L Board’s belief is that after a thorough review of other business combination opportunities reasonably available to HH&L, the Business Combination represents the best potential business combination for HH&L and its shareholders based upon the process utilized to evaluate and assess other potential acquisition targets, and the HH&L Board believes that such process has not presented a better alternative.
Certainty of Closing of the Business Combination. On the basis that (i) the closing of the Business Combination is not subject to any minimum cash closing condition; and (ii) the shareholders of DiaCarta representing at least two-thirds of the outstanding DiaCarta ordinary shares and DiaCarta preference shares (on an as converted basis as of the date of the Merger Agreement) have entered into the DiaCarta Holders Support Agreements agreeing to vote in favor of the transactions contemplated by the Merger Agreement, the HH&L Board expected that the Business Combination can be consummated pursuant to the terms and conditions of the Merger Agreement.
Independent Directors’ Role. HH&L Board is comprised of a majority of independent directors who are not affiliated with the Sponsor or its affiliates. The independent directors evaluated and approved, as members of HH&L Board, the Merger Agreement and the transactions contemplated thereby, including the Business Combination.

For a more complete description of the HH&L Board’s reasons for approving the Business Combination, including other factors and risks considered by the HH&L Board, see “BCA Proposal—HH&L Board’s Reasons for the Approval of the Business Combination” beginning on page 183 of this proxy statement / prospectus.

Related Agreements

This section describes certain additional agreements entered into or to be entered into pursuant to the Merger Agreement. For additional information, see “BCA Proposal—Related Agreements” beginning on page 175 of this proxy statement / prospectus.

HH&L Holders Support Agreement

In connection with the execution of the Merger Agreement, HH&L, DiaCarta and certain shareholders of HH&L entered into a support agreement, dated as of October 14, 2022, a copy of which is attached to the accompanying proxy statement / prospectus as Annex B (the “HH&L Holders Support Agreement”). Pursuant to the HH&L Holders Support Agreement, such shareholders of HH&L agreed to, among other things, (i) vote in favor of the Merger Agreement and other documents contemplated thereby and the transactions contemplated thereby, including the Business Combination, (ii) for a certain period of time as set out in the HH&L Holders Support Agreement, not transfer any shares or warrants of HH&L, (iii) waive or not otherwise perfect any anti-dilution or

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similar protection with respect to any Founder Shares, and (iv) not redeem, or submit a request to redeem, any HH&L ordinary shares owned by such HH&L shareholders in connection with the transactions contemplated by the Merger Agreement or otherwise, in each case, subject to the terms and conditions contemplated by the HH&L Holders Support Agreement. For additional information, see “BCA Proposal—Related Agreements—HH&L Holders Support Agreement” beginning on page 175 of this proxy statement / prospectus.

DiaCarta Holders Support Agreement

In connection with the execution of the Merger Agreement, HH&L entered into a support agreement with DiaCarta and certain shareholders of DiaCarta, dated as of October 14, 2022, a copy of which is attached to the accompanying proxy statement / prospectus as Annex C (the “DiaCarta Holders Support Agreement”). Pursuant to the DiaCarta Holders Support Agreement, such shareholders of DiaCarta agreed to, among other things, vote their outstanding ordinary shares and preference shares of DiaCarta in favor of the Merger Agreement and the other documents contemplated thereby and the related transactions contemplated thereby, including the DiaCarta Domestication and the Merger, subject to the terms and conditions contemplated by the DiaCarta Holders Support Agreement and for a certain period of time set forth in the DiaCarta Holders Support Agreement, not transfer any shares of DiaCarta. For additional information, see “BCA Proposal—Related Agreements—DiaCarta Holders Support Agreement” beginning on page 176 of this proxy statement / prospectus.

Registration Rights Agreement

The Merger Agreement contemplates that, at the Closing, DiaCarta PubCo, Domesticated DiaCarta, the Sponsor, certain stockholders of DiaCarta PubCo and certain stockholders of Domesticated DiaCarta will enter into the Registration Rights Agreement, pursuant to which DiaCarta PubCo will agree to undertake certain resale shelf registration obligations in accordance with the Securities Act, and the holders party thereto, subject to certain requirements and customary conditions, will be granted customary demand and piggyback registration rights. For additional information, see “BCA Proposal—Related Agreements—Registration Rights Agreement” beginning on page 176 of this proxy statement / prospectus.

Lock-Up Agreement

Certain shareholders of HH&L and certain shareholders of DiaCarta will enter into the Lock-Up Agreement with DiaCarta PubCo at the Closing, pursuant to which such shareholders will agree, subject to certain customary exceptions, not to transfer any shares of DiaCarta PubCo common stock beginning on the Closing Date and ending on the earlier of (i) twelve (12) months after the Closing Date and (ii) subsequent to the Closing, the date on which (a) the closing trading price of the shares of DiaCarta PubCo common stock equals or exceeds $12.00 per share for any twenty (20) trading days within any thirty-day (30) trading period commencing one hundred and fifty (150) days after the Closing Date, or (b) DiaCarta PubCo completes a transaction that results in public shareholders having the right to exchange their common stock for cash, securities or other property. For additional information, see “BCA Proposal—Related Agreements—Lock-Up Agreement” beginning on page 176 of this proxy statement / prospectus.

Sponsor Shares Forfeiture Agreement

In connection with the execution of the Merger Agreement, HH&L and DiaCarta entered into a sponsor shares forfeiture agreement with the Sponsor, dated as of October 14, 2022, a copy of which is attached to the accompanying proxy statement / prospectus as Annex J (the “Sponsor Shares Forfeiture Agreement”). Pursuant to the Sponsor Shares Forfeiture Agreement, the Sponsor agreed to contribute or forfeit certain HH&L Class B ordinary shares owned by it to facilitate financing after the signing of the Merger Agreement and certain forfeiture arrangement with an agreed cap. For additional information, see “BCA Proposal—Related Agreements—Sponsor Shares Forfeiture Agreement” beginning on page 176 of this proxy statement / prospectus.

Ownership of DiaCarta PubCo following Business Combination

As of the date of this proxy statement / prospectus, there are 51,750,000 ordinary shares issued and outstanding (including those ordinary shares underlying the HH&L units), which includes the 10,350,000 HH&L Class B ordinary shares held by the Sponsor and certain directors of HH&L and the 41,400,000 public shares. As of the date of this proxy statement / prospectus, there is outstanding an aggregate of 30,980,000 warrants, which includes the 10,280,000 private placement warrants held by the Sponsor and 20,700,000 public warrants. Each whole warrant entitles the holder thereof to purchase one HH&L Class A ordinary share and,

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following the HH&L Domestication, will entitle the holder thereof to purchase one share of DiaCarta PubCo common stock. Therefore, as of the date of this proxy statement / prospectus (without giving effect to the Business Combination), the HH&L fully diluted share capital would be 82,730,000 ordinary shares.

It is anticipated that, following the Business Combination, (1) HH&L’s public shareholders are expected to own approximately 42.3% of the outstanding DiaCarta PubCo common stock, (2) the shareholders of DiaCarta (without taking into account any public shares held by the shareholders of DiaCarta prior to the consummation of the Business Combination) are expected to own approximately 47.1% of the outstanding DiaCarta PubCo common stock, and (3) the Sponsor and related parties are expected to collectively own approximately 10.6% of the outstanding DiaCarta PubCo common stock. These percentages assume (i) that no public shareholders exercise their redemption rights in connection with the Business Combination, (ii) (a) the vesting and exercise of all DiaCarta PubCo Options and Converted DiaCarta PubCo Warrants for shares of DiaCarta PubCo common stock (assuming that all DiaCarta PubCo Options and Converted DiaCarta PubCo Warrants are net-settled), and (b) that DiaCarta PubCo issues shares of DiaCarta PubCo common stock as the Aggregate Merger Consideration pursuant to the Merger Agreement, which in the aggregate equal to 46,000,000 shares of DiaCarta PubCo common stock (assuming that all DiaCarta PubCo Options and Converted DiaCarta PubCo Warrants are net-settled). If the actual facts are different from these assumptions, the percentage ownership retained by the Company’s existing shareholders in the combined company will be different.

The following table illustrates varying ownership levels in DiaCarta PubCo immediately following the consummation of the Business Combination based on the assumptions above.

    

Assuming No
Redemptions
(Shares)

    

%
Ownership

    

Assuming
Maximum
Redemptions(1)
(Shares)

    

%
Ownership

 

DiaCarta Equityholders

46,000,000

47.1

%  

46,000,000

76.3

%

HH&L Class A ordinary shares

41,400,000

42.3

%  

3,934,298

6.5

%

HH&L Class B ordinary shares

10,350,000

10.6

%  

10,350,000

17.2

%

Pro forma common stock outstanding at June 30, 2022

97,750,000

100

%

60,284,298

100

%

(1)Reflects maximum redemptions of 37,465,702 shares owned by public shareholders, assuming SPAC closing cash will meet the minimal threshold under the Sponsor Shares Forfeiture Agreement without any transaction financing.

Date, Time and Place of Extraordinary General Meeting of HH&L’s Shareholders

The extraordinary general meeting of the shareholders of HH&L will be held at                 , Eastern Time, on                 , at the offices of White & Case LLP at 1221 Avenue of the Americas, New York, New York 10020, or virtually via live webcast at https://www.cstproxy.com/hhlacquisition/2022, to consider and vote upon the proposals to be put to the extraordinary general meeting, including if necessary, the Adjournment Proposal, to permit further solicitation and vote of proxies if, based upon the tabulated vote at the time of the extraordinary general meeting, each of the Condition Precedent Proposals have not been approved.

Registering for the Special Meeting

Any shareholder wishing to attend the extraordinary general meeting should register for the extraordinary general meeting by                  at                 . To register for the extraordinary general meeting, please follow these instructions as applicable to the nature of your ownership of ordinary shares:

If your shares are registered in your name with Continental Stock Transfer & Trust Company and you wish to attend the online-only meeting, go to https://www.cstproxy.com/hhlacquisition/2022, enter the 12-digit control number included on your proxy card or notice of the extraordinary general meeting and click on the “Click here to preregister for the online meeting” link at the top of the page. Just prior to the start of the extraordinary general meeting you will need to log back into the extraordinary general meeting site using your control number. Pre-registration is recommended but is not required in order to attend.

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Beneficial shareholders (those holding shares through a stock brokerage account or by a bank or other holder of record) who wish to attend the extraordinary general meeting must obtain a legal proxy by contacting their account representative at the bank, broker, or other nominee that holds their shares and e-mail a copy (a legible photograph is sufficient) of their legal proxy to proxy@continentalstock.com. Beneficial shareholders who e-mail a valid legal proxy will be issued a 12-digit meeting control number that will allow them to register to attend and participate in the extraordinary general meeting. After contacting Continental Stock Transfer & Trust Company, a beneficial holder will receive an e-mail prior to the extraordinary general meeting with a link and instructions for entering the extraordinary general meeting. Beneficial shareholders should contact Continental Stock Transfer & Trust Company at least five (5) business days prior to the extraordinary general meeting date in order to ensure access.

Voting Power; Record Date

HH&L shareholders will be entitled to vote or direct votes to be cast at the extraordinary general meeting if they owned ordinary shares at the close of business on                 , which is the record date for the extraordinary general meeting. Shareholders will have one vote for each ordinary share owned at the close of business on the record date. If your shares are held in “street name” or are in a margin or similar account, you should contact your broker to ensure that votes related to the shares you beneficially own are properly counted. HH&L warrants do not have voting rights. As of the close of business on the most recent practicable date before the date of this proxy statement / prospectus, there were 51,750,000 ordinary shares issued and outstanding (including those ordinary shares underlying the HH&L units), of which 41,400,000 were public shares, with the rest being held by the Sponsor and certain HH&L’s directors.

Quorum and Vote of HH&L Shareholders

A quorum of HH&L shareholders is necessary to hold a valid meeting. A quorum will be present at the HH&L general meeting if the holders of a majority of the issued shares entitled to vote at the extraordinary general meeting are represented in person or by proxy (which would include presence at the extraordinary general meeting). Abstentions and broker non-votes, while considered present for the purposes of establishing a quorum, will not count as a vote cast at the extraordinary general meeting.

As of the most recent practicable date before the date of this proxy statement / prospectus, 15,525,001 HH&L Class A ordinary shares would be required to achieve a quorum.

The Sponsor and certain directors and officers of HH&L have agreed to vote all of their HH&L Class B ordinary shares in favor of the proposals being presented at the extraordinary general meeting. As of the date of this proxy statement / prospectus, the Sponsor and such directors and officers owns approximately 20% of the issued and outstanding HH&L ordinary shares.

The proposals presented at the extraordinary general meeting require the following votes:

BCA Proposal: The approval of the BCA Proposal (including the Merger) requires a special resolution, being the affirmative vote for the proposal by the holders of a majority of at least two-thirds of the ordinary shares who, being present and entitled to vote at the extraordinary general meeting to approve the BCA Proposal, vote at the quorate extraordinary general meeting.
Class B Conversion Proposal: The approval of the Class B Conversion Proposal requires a special resolution under the Cayman Constitutional Documents, being the affirmative vote for the proposal by the holders of a majority of at least two-thirds of the ordinary shares who, being present and entitled to vote at the extraordinary general meeting to approve the Class B Conversion Proposal, vote at the quorate extraordinary general meeting.
Domestication Proposal: The approval of the Domestication Proposal requires a special resolution under the Cayman Constitutional Documents, being the affirmative vote for the proposal by the holders of a majority of at least two-thirds of the ordinary shares who, being present and entitled to vote at the extraordinary general meeting to approve the Domestication Proposal, vote at the quorate extraordinary general meeting.

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Organizational Documents Proposal: The approval of the Organizational Documents Proposal (including the amendment of the Cayman Constitutional Documents) requires a special resolution under the Cayman Islands Companies Act, being the affirmative vote for the proposal by the holders of a majority of at least two-thirds of the ordinary shares who, being present and entitled to vote at the extraordinary general meeting to approve the Organizational Documents Proposal, vote at the quorate extraordinary general meeting.
Advisory Organizational Documents Proposals: The separate approval of each of the Advisory Organizational Documents Proposals requires a special resolution under the Cayman Islands Companies Act, being the affirmative vote for each of the Advisory Organizational Documents Proposals by the holders of a majority of at least two-thirds of the ordinary shares who, being present and entitled to vote at the extraordinary general meeting to approve each such Advisory Organizational Documents Proposal, vote at the quorate extraordinary general meeting.
Director Election Proposal: The approval of the Director Election Proposal requires an ordinary resolution under the Cayman Constitutional Documents, being the affirmative vote of holders of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon and who voted at the quorate extraordinary general meeting. Under the terms of the Cayman Constitutional Documents, only the holders of HH&L Class B ordinary shares are entitled to vote on the election of directors to the HH&L Board. Therefore, only holders of the HH&L Class B ordinary shares will vote on the election of directors at the quorate extraordinary general meeting. Neither the failure to vote or abstentions of holders of HH&L Class A ordinary shares will have any effect on the outcome of the proposal.
Stock Issuance Proposal: The Stock Issuance Proposal is being proposed for approval by way of ordinary resolution, being the affirmative vote for the proposal by the holders of a majority of the ordinary shares who, being present and entitled to vote at the extraordinary general meeting to approve the Stock Issuance Proposal, vote at the quorate extraordinary general meeting.
Equity Incentive Plan Proposal: The Equity Incentive Plan Proposal is being proposed for approval by way of ordinary resolution, being the affirmative vote for the proposal by the holders of a majority of the ordinary shares who, being present and entitled to vote at the extraordinary general meeting to approve the Equity Incentive Plan Proposal, vote at the quorate extraordinary general meeting.
Adjournment Proposal: The Adjournment Proposal is being proposed for approval by way of ordinary resolution, being the affirmative vote for the proposal by the holders of a majority of the ordinary shares who, being present and entitled to vote at the extraordinary general meeting to approve the Adjournment Proposal, vote at the quorate extraordinary general meeting.

Abstentions and broker non-votes, while considered present for the purposes of establishing a quorum, will not count as a vote cast at the extraordinary general meeting.

Redemption Rights

Pursuant to the Cayman Constitutional Documents, a public shareholder may request of HH&L that DiaCarta PubCo redeem all or a portion of its public shares for cash if the Business Combination is consummated. As a holder of public shares, you will be entitled to receive cash for any public shares to be redeemed only if you:

hold public shares or if you hold public shares through HH&L units, you elect to separate your HH&L units into the underlying public shares and public warrants prior to exercising your redemption rights with respect to the public shares;
submit a written request to Continental, HH&L’s transfer agent, that DiaCarta PubCo redeem all or a portion of your public shares for cash; and
deliver the certificates for your public shares (if any) along with the redemption forms to Continental physically or electronically through DTC.

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Holders must complete the procedures for electing to redeem their public shares in the manner described above prior to                 , Eastern Time, on                  (two business days before the extraordinary general meeting) in order for their shares to be redeemed.

Holders of HH&L units must elect to separate the HH&L units into the underlying public shares and public warrants prior to exercising redemption rights with respect to the public shares. If holders hold their HH&L units in an account at a brokerage firm or bank, holders must notify their broker or bank that they elect to separate the HH&L units into the underlying public shares and public warrants, or if a holder holds HH&L units registered in its own name, the holder must contact Continental directly and instruct them to do so. Public shareholders may elect to redeem all or a portion of the public shares held by them regardless of if or how they vote in respect of the BCA Proposal. If the Business Combination is not consummated, the public shares will be returned to the respective holder, broker or bank. If the Business Combination is consummated, and if a public shareholder properly exercises its right to redeem all or a portion of the public shares that it holds and timely delivers the certificates for its shares (if any) along with the redemption forms to Continental, DiaCarta PubCo will redeem such public shares for a per-share price, payable in cash, equal to the pro rata portion of the trust account, calculated as of two business days prior to the consummation of the Business Combination. For illustrative purposes, as of June 30, 2022, this would have amounted to approximately $10.02 per issued public share. If a public shareholder exercises its redemption rights in full, then it will be electing to exchange its public shares for cash and will no longer own public shares. The redemption takes place following the HH&L Domestication and, accordingly, it is shares of DiaCarta PubCo common stock that will be redeemed immediately after consummation of the Business Combination. See “Extraordinary General Meeting of HH&L—Redemption Rights” in this proxy statement / prospectus for a detailed description of the procedures to be followed if you wish to redeem your public shares for cash.

Notwithstanding the foregoing, a public shareholder, together with any affiliate of such public shareholder or any other person with whom such public shareholder is acting in concert or as a “group” (as defined in Section 13(d)(3) of the Exchange Act), will be restricted from redeeming its public shares with respect to more than an aggregate of 20% of the public shares. Accordingly, if a public shareholder, alone or acting in concert or as a group, seeks to redeem more than 20% of the public shares, then any such shares in excess of that 20% limit would not be redeemed for cash.

The Sponsor has agreed to vote in favor of the Business Combination, regardless of how HH&L’s public shareholders vote. The Sponsor and each director and each officer of HH&L have agreed to, among other things, vote in favor of the Merger Agreement and the transactions contemplated thereby, subject also to the terms and conditions contemplated by the HH&L Holders Support Agreement. As of the date of this proxy statement / prospectus, the Sponsor owns approximately 20% of the issued and outstanding ordinary shares.

Holders of the warrants will not have redemption rights with respect to the warrants.

Appraisal Rights

Neither HH&L’s shareholders nor HH&L’s warrant holders have appraisal rights in connection with the Business Combination or the HH&L Domestication under Cayman Islands law. HH&L’s shareholders who has voted in favor of the Business Combination and the HH&L Domestication and who is entitled to demand and has exercised appraisal rights of their shares in accordance with Section 262 of the DGCL shall be entitled to such rights as are granted by Section 262 of the DGCL.

Proxy Solicitation

Proxies may be solicited by mail, telephone or in person. HH&L has engaged Morrow Sodali LLC to assist in the solicitation of proxies.

If a shareholder grants a proxy, it may still vote its shares in person if it revokes its proxy before the extraordinary general meeting. A shareholder also may change its vote by submitting a later-dated proxy as described in the section entitled “Extraordinary General Meeting of HH&L—Revoking Your Proxy.”

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Interests of HH&L Directors and Officers in the Business Combination

When you consider the recommendation of HH&L Board in favor of approval of the BCA Proposal, you should keep in mind that the Sponsor and HH&L’s directors and executive officers have interests in such proposal that are different from, or in addition to, those of HH&L shareholders and warrant holders generally. These interests include, among other things, the interests listed below:

Prior to HH&L’s initial public offering, the Sponsor purchased 14,375,000 HH&L Class B ordinary shares for an aggregate purchase price of $25,000, or approximately $0.002 per Founder Share, on September 7, 2020. On January 20, 2021, the Sponsor returned 5,750,000 HH&L Class B ordinary shares for no consideration, following which, the Sponsor holds 8,625,000 Founder Shares. On February 4, 2021, the Sponsor transferred an aggregate of 66,000 HH&L Class B ordinary shares to three independent directors. On February 4, 2021, HH&L effected a share dividend of 1,725,000 HH&L Class B ordinary shares, resulting in an aggregate of 10,350,000 HH&L Class B ordinary shares outstanding. On May 19, 2021, the Sponsor transferred 22,000 HH&L Class B ordinary shares to Skyview Enterprises Limited, an affiliate of Derek Sulger, an independent director of HH&L, for his board service for no cash consideration. As of June 30, 2022, the Sponsor held 10,262,000 HH&L Class B ordinary shares. As a result of the significantly lower investment per HH&L Class B ordinary share of the Sponsor as compared with the investment per public share of HH&L’s public shareholders, a transaction which results in an increase in the value of the investment of the Sponsor may result in a decrease in the value of the investment of our public shareholders.
If HH&L does not consummate a business combination by February 9, 2023 (or the Extended Deadline), it would cease all operations except for the purpose of winding up, redeeming all of the outstanding public shares for cash and, subject to the approval of its remaining shareholders and its board of directors, liquidating and dissolving, subject in each case to its obligations under Cayman Islands law to provide for claims of creditors and the requirements of other applicable law. In such event, the 10,262,000 HH&L Class B ordinary shares owned by the Sponsor would be worthless because following the redemption of the public shares, HH&L would likely have few, if any, net assets. Additionally, in such event, the 10,280,000 private placement warrants purchased by the Sponsor simultaneously with the consummation of HH&L’s initial public offering for an aggregate purchase price of $10,280,000 will also expire worthless.
HH&L’s directors and officers, Huanan Yang, Yingjie (Christina) Zhong, Qingjun Jin, Dr. Jingwu Zhang Zang, Professor Frederick Si Hang Ma and Derek Nelsen Sulger, also have a direct or indirect economic interest in the HH&L Class B ordinary shares. The 10,350,000 shares of DiaCarta PubCo common stock into which the 10,350,000 HH&L Class B ordinary shares held by the Sponsor and certain HH&L’s directors and officers will automatically convert in connection with the Merger (including after giving effect to the HH&L Domestication), if unrestricted and freely tradable, would have had an aggregate market value of $       million based upon the closing price of $         per public share on the NYSE on        , the most recent practicable date prior to the date of this proxy statement / prospectus. However, given that such shares of DiaCarta PubCo common stock will be subject to certain restrictions, including those described elsewhere in this proxy statement / prospectus, HH&L believes such shares have less value. The 10,280,000 DiaCarta PubCo warrants into which the 10,280,000 private placement warrants held by the Sponsor will automatically convert in connection with the Merger (including after giving effect to the HH&L Domestication), if unrestricted and freely tradable, would have had an aggregate market value of $        million based upon the closing price of $      per public warrant on the NYSE on        , the most recent practicable date prior to the date of this proxy statement / prospectus. However, given that such DiaCarta PubCo warrants will be subject to certain restrictions, including those described elsewhere in this proxy statement / prospectus, HH&L believes such warrants have less value.
Accordingly, the Sponsor, officers and directors will lose their entire investment of $10,305,000, consisting of the Sponsor’s $25,000 initial investment and the Sponsor’s $10,280,000 private placement warrant purchase price, if HH&L does not complete a business combination by February 9, 2023 (or the Extended Deadline).
Pursuant to that certain letter agreement, dated as of February 5, 2021, by and among the HH&L, its executive officers, its directors, its advisory board member and the Sponsor, in connection with HH&L’s initial public offering, the Sponsor and other signatories (each of whom is a member of HH&L Board, advisory board member and/or executive officers) is subject

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to certain restrictions on transfer with respect to: (i) HH&L Class B ordinary shares (as defined in such letter agreement); and (ii) private placement warrants (as defined in such letter agreement). Such restrictions on the HH&L Class B ordinary shares end on the date that is one year after Closing, or are subject to an early price-based release if: (a) the price of the shares equals or exceeds $12.00 per share for any twenty trading days within any thirty-day trading period at least 150 days after the Business Combination, or (b) HH&L completes a transaction that results in public shareholders having the right to exchange the HH&L Class A ordinary shares for cash, securities or other property. The restrictions on the private placement warrants end on 30 days after the completion of a business combination.
The Sponsor and each member of HH&L Board, advisory board member and/or executive officers irrevocably and unconditionally agreed that if HH&L seeks shareholder approval of a proposed Business Combination, then in connection with proposed Business Combination, such Sponsor and insider shall not elect to cause HH&L to redeem any of the 10,350,000 HH&L Class B ordinary shares and 10,280,000 private placement warrants beneficially owned or owned of record by such Sponsor or insider, or submit any of such securities for redemption, in connection with the transactions contemplated by the Merger Agreement or otherwise.
The Sponsor, officers and directors have agreed to waive their rights to liquidating distributions from the trust account with respect to their Founder Shares if HH&L fails to complete a business combination by February 9, 2023 (or the Extended Deadline).
HH&L’s existing directors and officers will be eligible for continued indemnification and continued coverage under HH&L’s directors’ and officers’ liability insurance policy after the Merger and pursuant to the Merger Agreement.
Following the Closing, the Sponsor would be entitled to the repayment of any working capital loan and advances that have been made to HH&L and remain outstanding. If HH&L does not complete an initial business combination within the required period, HH&L may use a portion of its working capital held outside the trust account to repay the working capital loans, but no proceeds held in the trust account would be used for this purpose. As of the date of this proxy statement / prospectus, HH&L has $500,000 amount of borrowings under an unsecured convertible promissory notes issued to the Sponsor, dated September 15, 2022.
The Sponsor, officers and directors and their affiliates are entitled to reimbursement of out-of-pocket expenses incurred by them related to identifying, investigating, negotiating and completing an initial business combination, including repayment of any other loans and advances made. However, if HH&L fails to consummate a business combination by February 9, 2023 (or the Extended Deadline), they will not have any claim against the trust account for reimbursement. Accordingly, HH&L may not be able to reimburse these expenses if the Business Combination or another business combination is not completed by such date.
Pursuant to the Registration Rights Agreement, the Sponsor, certain of its respective affiliates and certain shareholders of DiaCarta will have customary registration rights, including demand and piggy-back rights, subject to cooperation and cut-back provisions with respect to the shares of DiaCarta PubCo common stock and warrants held by such parties following the consummation of the Business Combination.
The Proposed Certificate of Incorporation will contain a provision expressly electing that DiaCarta PubCo will not to be governed by Section 203 (Delaware’s “interested stockholder” statute) of the DGCL, although it will provide other restrictions regarding takeovers by interested stockholders.
Although the Sponsor and its affiliates have committed considerable capital to HH&L, including through its participation in the IPO and its contribution of a portion of the promote for no consideration, if the Business Combination is consummated, taking into account the investments described above, including the promote, it is possible that the Sponsor and its affiliates could realize a positive rate of return on such investments even if other HH&L shareholders experience a negative rate of return following the Business Combination.

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The Sponsor will benefit economically from the completion of a Business Combination and may be incentivized to complete an acquisition of a less favorable target company or on terms less favorable to shareholders rather than liquidate. That said, the Sponsor by pursuing a business combination with a less favorable target company or on terms less favorable to shareholders than what it would normally negotiate, may cause irreparable reputational damage to the Sponsor, which far exceeds to the dollar value of the Founder Shares, and this risk similarly serves as a disincentive from pursuing an unattractive business combination.

The Sponsor has agreed to vote in favor of the Business Combination, regardless of how HH&L’s public shareholders vote. The Sponsor and each director and each officer of HH&L have agreed to, among other things, vote in favor of the Merger Agreement and the transactions contemplated thereby, subject also to the terms and conditions contemplated by the HH&L Holders Support Agreement. As of the date of this proxy statement / prospectus, the Sponsor owns approximately 20% of the issued and outstanding ordinary shares.

At any time at or prior to the Business Combination, during a period when they are not then aware of any material non-public information regarding HH&L or HH&L’s securities, the Sponsor, DiaCarta our or their respective directors, officers, advisors or respective affiliates may purchase public shares from institutional and other investors who vote, or indicate an intention to vote, against any of the Condition Precedent Proposals, or execute agreements to purchase such shares from such investors in the future, or they may enter into transactions with such investors and others to provide them with incentives to acquire public shares or vote their public shares in favor of the Condition Precedent Proposals. Such a purchase may include a contractual acknowledgement that such shareholder, although still the record holder of HH&L’s shares, is no longer the beneficial owner thereof and therefore agrees not to exercise its redemption rights. In the event that the Sponsor, DiaCarta or their respective directors, officers, advisors or respective affiliates purchase shares in privately negotiated transactions from public shareholders who have already elected to exercise their redemption rights, such selling shareholder would be required to revoke their prior elections to redeem their shares. The purpose of such share purchases and other transactions would be to increase the likelihood of (1) satisfaction of the requirement that holders of a majority of the ordinary shares, represented in person or by proxy and entitled to vote at the extraordinary general meeting, vote in favor of the Director Election Proposal, the Stock Issuance Proposal, the Equity Incentive Plan Proposal and the Adjournment Proposal, (2) satisfaction of the requirement that holders of a majority of at least two-thirds of the ordinary shares, represented in person or by proxy and entitled to vote at the extraordinary general meeting, vote in favor of the BCA Proposal, the Class B Conversion Proposal, the Domestication Proposal, the Organizational Documents Proposal, and the Advisory Organizational Documents Proposals, (3) otherwise limiting the number of public shares electing to redeem and (4) HH&L’s net tangible assets being at least $5,000,001.

Entering into any such arrangements may have a depressive effect on the ordinary shares (e.g., by giving an investor or holder the ability to effectively purchase shares at a price lower than market, such investor or holder may therefore become more likely to sell the shares it, he or she owns, either at or prior to the Business Combination). If such transactions are effected, the consequence could be to cause the Business Combination to be consummated in circumstances where such consummation could not otherwise occur. Purchases of shares by the persons described above would allow them to exert more influence over the approval of the proposals to be presented at the extraordinary general meeting and would likely increase the chances that such proposals would be approved.

The existence of financial and personal interests of one or more of HH&L’s directors may result in a conflict of interest on the part of such director(s) between what he, she or they may believe is in the best interests of HH&L and its shareholders and what he, she or they may believe is best for himself, herself or themselves in determining to recommend that shareholders vote for the proposals. In addition, HH&L’s officers have interests in the Business Combination that may conflict with your interests as a shareholder. See “—Interests of HH&L’s Directors and Officers in the Business Combination” for a further discussion of these considerations.

Recommendation to Shareholders of HH&L

HH&L Board believes that the BCA Proposal and the other proposals to be presented at the extraordinary general meeting are in the best interests of HH&L’s shareholders and unanimously recommends that its shareholders vote “FOR” the approval of the BCA Proposal, “FOR” the approval of the Class B Conversion Proposal, “FOR” the approval of the Domestication Proposal, “FOR” the approval of the Organizational Documents Proposal, “FOR” the approval of each of the separate Advisory Organizational Documents Proposals, “FOR” the approval of the Director Election Proposal, “FOR” the approval of the Stock Issuance Proposal, “FOR” the

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approval of the Equity Incentive Plan Proposal and “FOR” the approval of the Adjournment Proposal, in each case, if presented to the extraordinary general meeting.

The existence of financial and personal interests of one or more of HH&L’s directors may result in a conflict of interest on the part of such director(s) between what he, she or they may believe is in the best interests of HH&L and its shareholders and what he, she or they may believe is best for himself, herself or themselves in determining to recommend that shareholders vote for the proposals. In addition, HH&L’s officers have interests in the Business Combination that may conflict with your interests as a shareholder. See “BCA Proposal—Interests of HH&L’s Directors and Executive Officers in the Business Combination” for a further discussion of these considerations.

Sources and Uses of Funds for the Business Combination

The following table summarizes the sources and uses for funding the transactions contemplated by the Merger Agreement. Where actual amounts are not known or knowable, the figures below represent HH&L’s good faith estimate of such amounts assuming a Closing as of      .

    

Assuming No
Redemption

    

Assuming
Maximum
Redemption

 

(in millions)

Sources

Proceeds from Trust Account

$

414,000,000

$

40,000,000

DiaCarta’s Equity (1)

460,000,000

460,000,000

Sponsor Shares

103,500,000

103,500,000

Total Sources

$

977,500,000

$

603,500,000

Uses

Cash on Balance Sheet

$

394,000,000

$

20,000,000

DiaCarta’s Equity (1)

460,000,000

460,000,000

Sponsor Shares

103,500,000

103,500,000

Transaction costs(2)

20,000,000

20,000,000

Total Uses

$

977,500,000

$

603,500,000

(1)

DiaCarta PubCo common stock to be issued at a deemed value of $10.00 per share.

(2)

Reflects estimated transaction expenses, including the deferred advisor fee, up to $2 million, that HH&L may , in its discretion, pay Cohen & Company Capital Markets in the form of shares of DiaCarta PubCo common stock, for its service as financial advisor to HH&L in connection with the Business Combination. Pursuant to a letter addressed to HH&L from Goldman Sachs (Asia) L.L.C. (“Goldman Sachs”), dated October 7, 2022, and a letter executed by HH&L and Credit Suisse Securities (USA) LLC (“Credit Suisse”), dated October 13, 2022, each of Goldman Sachs and Credit Suisse waived any entitlement to their respective portions of the $14,490,000 underwriting commission fee.

U.S. Federal Income Tax Considerations

For a discussion summarizing certain U.S. federal income tax considerations of the Domestication and an exercise of redemption rights in connection with the Business Combination, please see “U.S. Federal Income Tax Considerations” beginning on page 219 of this proxy statement / prospectus.

Expected Accounting Treatment

The HH&L Domestication

There will be no accounting effect or change in the carrying amount of the consolidated assets and liabilities of HH&L as a result of the HH&L Domestication. The business, capitalization, assets and liabilities and financial statements of DiaCarta PubCo immediately following the HH&L Domestication will be the same as those of HH&L immediately prior to the HH&L Domestication.

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The Business Combination

We expect the Business Combination to be accounted for as a reverse recapitalization in accordance with GAAP. Under the guidance in ASC 805, HH&L is expected to be treated as the “acquired” company for financial reporting purposes. Accordingly, the Business Combination is expected to be reflected as the equivalent of DiaCarta issuing stock for the net assets of HH&L, accompanied by a recapitalization whereby no goodwill or other intangible assets are recorded.

Regulatory Matters

Under the HSR Act and the rules that have been promulgated thereunder by the Federal Trade Commission (“FTC”), certain transactions may not be consummated unless information has been furnished to the Antitrust Division of the Department of Justice (“Antitrust Division”) and the FTC and certain waiting period requirements have been satisfied. The Business Combination is subject to these requirements and may not be completed until the expiration of a 30-day waiting period following the two filings of the required Notification and Report Forms with the Antitrust Division and the FTC or until early termination is granted. On                 , HH&L and DiaCarta filed the required forms under the HSR Act with respect to the Business Combination with the Antitrust Division and the FTC and requested early termination. On                 , both DiaCarta and HH&L received notice that early termination had been granted.

At any time before or after consummation of the Business Combination, notwithstanding termination of the respective waiting periods under the HSR Act, the Antitrust Division or the FTC, or any state or foreign governmental authority could take such action under applicable antitrust laws as such authority deems necessary or desirable in the public interest, including seeking to enjoin the consummation of the Business Combination, conditionally approving the Business Combination upon divestiture of assets, subjecting the completion of the Business Combination to regulatory conditions or seeking other remedies. Private parties may also seek to take legal action under the antitrust laws under certain circumstances. HH&L cannot assure you that the Antitrust Division, the FTC, any state attorney general or any other government authority will not attempt to challenge the Business Combination on antitrust grounds, and, if such a challenge is made, HH&L cannot assure you as to its result.

Neither HH&L nor DiaCarta are aware of any material regulatory approvals or actions that are required for completion of the Business Combination other than the expiration or early termination of the waiting period under the HSR Act. It is presently contemplated that if any such additional regulatory approvals or actions are required, those approvals or actions will be sought. There can be no assurance, however, that any additional approvals or actions will be obtained.

Emerging Growth Company

HH&L is an “emerging growth company,” as defined in Section 2(a) of the Securities Act, as modified by the JOBS Act, and it may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies, including, but not limited to, not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act, reduced disclosure obligations regarding executive compensation in HH&L’s periodic reports and proxy statements, and exemptions from the requirements of holding a non-binding advisory vote on executive compensation and stockholder approval of any golden parachute payments not previously approved.

Further, section 102(b)(1) of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Exchange Act) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that a company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging growth companies, but any such election to opt out is irrevocable. HH&L has elected not to opt out of such extended transition period, which means that when a standard is issued or revised and it has different application dates for public or private companies, HH&L, as an emerging growth company, can adopt the new or revised standard at the time private companies adopt the new or revised standard. This may make comparison of HH&L’s financial statements with certain other public companies difficult or impossible because of the potential differences in accounting standards used.

HH&L will remain an emerging growth company until the earlier of: (1) the last day of the fiscal year (a) following the fifth anniversary of the closing of HH&L’s initial public offering, (b) in which HH&L has total annual gross revenue of at least $1.235 billion or (c) in which HH&L is deemed to be a large accelerated filer, which means the market value of HH&L’s common

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equity that is held by non-affiliates exceeds $700 million as of the end of the prior fiscal year’s second fiscal quarter; and (2) the date on which HH&L has issued more than $1.00 billion in non-convertible debt securities during the prior three-year period. References herein to “emerging growth company” shall have the meaning associated with it in the JOBS Act.

Additionally, HH&L is a “smaller reporting company” as defined in Item 10(f)(1) of Regulation S-K. Smaller reporting companies may take advantage of certain reduced disclosure obligations, including, among other things, providing only two years of audited financial statements. HH&L will remain a smaller reporting company until the last day of the fiscal year in which (1) the market value of its common equity held by non-affiliates exceeds $700 million as of the prior June 30th or (2) the market value of its common equity exceeds $250 million and its annual revenues exceeds $100 million during such fiscal year.

Risk Factors

In evaluating the proposals to be presented at the extraordinary general meeting, shareholders should carefully read this proxy statement / prospectus and especially consider the factors discussed in the sections titled “Risk Factor Summary” and “Risk Factors” beginning on page 61 of this proxy statement / prospectus. In particular, such risks include, but are not limited to, the following:

The Sponsor has agreed to vote in favor of the Business Combination, regardless of how HH&L’s public shareholders vote.
DiaCarta has a history of net losses.
DiaCarta expects to incur materially higher expenses from being a public company.
DiaCarta’s current or future products may not achieve or maintain sufficient market acceptance.
DiaCarta does not yet have effective disclosure controls and procedures, and internal control over financial reporting.
If DiaCarta fails to retain sales and marketing personnel or fails to increase our marketing and sales prowess, it may not be able to generate revenue growth; DiaCarta’s in-house sales function may reduce flexibility and competitiveness.
DiaCarta’s current line of diagnostic tests is covered under CLIA and CMS, although its COVID testing program and select partnerships it may enter may cause DiaCarta to be subject to additional FDA requirements.
Healthcare reform measures could impede or prevent the commercial success of DiaCarta’s products and services.
New product development and commercialization involve a lengthy and complex process and DiaCarta may be unable to develop or commercialize new products on a timely basis, or at all.
Clinical development involves lengthy and expensive processes with an uncertain outcome, and results of earlier studies and trials may not be predictive of future trial results.
A pandemic, epidemic or outbreak of an infectious disease could adversely affect DiaCarta’s business and DiaCarta may be unable to develop responsive products and services in a timely manner; there can be no assurance that DiaCarta will continue to successfully offer COVID-19 testing kits and services.
Failure to comply with U.S. federal, state, and foreign laboratory licensing requirements and the applicable requirements of the FDA or any other regulatory authority, could cause DiaCarta to lose the ability to perform tests, experience disruptions to its business, or become subject to administrative or judicial sanctions.
Success depends on DiaCarta’s ability to develop, receive regulatory clearance or approval or certification for, and introduce new diagnostic tests or enhancements to existing diagnostic tests that will be accepted by the market in a timely manner. There is no guarantee that the FDA will grant 510(k) clearance or PMA approval of future diagnostic tests.

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Developing new or improved diagnostic tests is an expensive, speculative and risky endeavor which may not be successful.
If DiaCarta cannot maintain its current relationships, or enter into new relationships, with biopharmaceutical companies, its revenue prospects could be reduced.
DiaCarta’s business and reputation will suffer if it is unable to establish and comply with stringent quality standards to assure that the highest level of quality is observed
DiaCarta’s operating results may fluctuate materially, which makes its future operating results difficult to predict and could cause its operating results to fall below expectations or any guidance DiaCarta may provide.
DiaCarta’s success could be impaired if it is unable to obtain, maintain and protect its intellectual property rights.
If DiaCarta is unable to protect the confidentiality of its trade secrets, DiaCarta’s business and competitive position could be damaged.
DiaCarta’s use, disclosure, and other processing of personally identifiable information, including health information, is subject to HIPAA and other U.S. federal, state, and foreign privacy and security regulations, and any failure to comply with those regulations or to adequately secure such information could result in significant liability or reputational harm.
Significant portions of DiaCarta’s operations are located outside of the United States, which subjects DiaCarta to additional risks, including increased complexity and costs of managing international operations and geopolitical instability.
DiaCarta’s PRC subsidiaries, and associated operations and revenues, are subject to PRC risks, including changes in the political and economic policies of the PRC government; reliance on third-party testing institutions for PRC operations; uncertainty whether new and proposed laws and regulations (some of which have been identified for increased enforcement and scrutiny) apply to DiaCarta’s PRC subsidiaries or their operations; DiaCarta’s PRC subsidiaries have not made adequate social insurance and housing fund contributions for all employees; DiaCarta’s PRC subsidiaries collect and handle a large amount of personal data, and the improper handling of or unauthorized access to such data could subject DiaCarta’s PRC subsidiaries to penalties or harm DiaCarta’s reputation
The process of taking a company public by means of a merger with a special purpose acquisition company is different from taking a company public through a traditional initial public offering and may create risks for our unaffiliated investors.
HH&L and DiaCarta will incur significant transaction and transition costs in connection with the Business Combination.
HH&L and DiaCarta may not be able to obtain transaction financing in connection with the Business Combination.
We may be forced to close the Merger even if we determined it is no longer in HH&L shareholders’ best interest.
HH&L’s current directors and officers and their affiliates have interests that are different than, or in addition to (and which may conflict with), the interests of its shareholders, and therefore potential conflicts of interest exist in recommending that shareholders vote in favor of approval of the Merger. Such conflicts of interests include that the Sponsor, as well as HH&L’s directors, officers and affiliates are expected to lose their entire investment in HH&L if the Merger is not completed.
The exercise of HH&L’s directors’ discretion in agreeing to changes or waivers in the terms of the Merger may result in a conflict of interest when determining whether such changes to the terms of the Merger or waivers of conditions are appropriate and in HH&L’s best interest.

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SELECTED HISTORICAL FINANCIAL INFORMATION OF HH&L

The following table sets forth selected historical financial information derived from HH&L’s unaudited financial statements as of and for the six months ended June 30, 2022 and HH&L’s audited financial statements as of and for the year ended December 31, 2021 and for the period from September 4, 2020 (inception) through December 31, 2020, each of which is included elsewhere in this proxy statement / prospectus. Such financial information should be read in conjunction with the audited and unaudited financial statements and related notes included elsewhere in this proxy statement / prospectus.

The historical results presented below are not necessarily indicative of the results to be expected for any future period. You should read the following summary financial information in conjunction with the section entitled “HH&L’s Management’s Discussion and Analysis of Financial Condition and Results of Operations” and HH&L’s financial statements and the related notes appearing elsewhere in this proxy statement / prospectus.

    

For the Six
Months Ended
June 30, 2022
(unaudited)

    

For the Year
Ended
December 31, 2021

    

For the Period
from September 4,
2020 (inception)
through
December 31, 2020

 

Statement of Operations Data:

General and administrative expenses

$

1,103,931

$

1,640,492

$

12,681

Administrative expenses – related party

90,000

165,000

Loss from operations

(1,193,931)

(1,805,492)

(12,681)

Other (expense) income:

Change in fair value of derivative warrant liabilities

12,082,200

3,923,200

Financing cost – derivative warrant liabilities

(821,170)

Income from investments held in Trust Account

621,817

23,891

Net income (loss)

11,510,086

1,320,429

(12,681)

Basic and diluted weighted average shares outstanding of Class A ordinary shares

41,400,000

36,976,438

Basic and diluted net income (loss) per ordinary share, Class A

$

0.22

$

0.03

$

Basic weighted average shares outstanding of Class B ordinary shares

10,350,000

10,205,753

9,000,000

Diluted weighted average shares outstanding of Class B ordinary shares

10,350,000

10,350,000

9,000,000

Basic and diluted net income (loss) per ordinary share, Class B

$

0.22

$

0.03

$

(0.00)

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June 30,

December 31,

Balance Sheet Data:

2022

2021

2020

Assets

    

    

    

    

    

    

 

Current assets:

Cash

$

11,309

$

399,935

$

6,410

Prepaid expenses

232,193

326,283

17,000

Total current assets

243,502

726,218

23,410

Deferred offering costs

439,752

Investments held in Trust Account

414,645,808

414,023,891

Total Assets

$

414,889,210

$

414,750,109

$

463,162

Liabilities, Class A Ordinary Shares Subject to Possible Redemption and Shareholders’ Equity (Deficit):

Current liabilities:

Accounts payable

$

283,487

$

176,063

$

116,374

Accrued expenses

1,502,616

988,825

194,520

Accounts payable - related party

255,000

165,000

Note payable - related party

139,949

Total current liabilities

2,041,103

1,329,888

450,843

Derivative warrant liabilities

5,266,600

17,348,800

Deferred underwriting commissions

14,490,000

14,490,000

Total liabilities

21,797,703

33,168,688

450,843

Commitments and Contingencies

Class A ordinary shares subject to possible redemption, $0.0001 par value; 41,400,000 and 0 shares at $10.00 per share redemption value as of December 31, 2021 and 2020, respectively

414,545,708

414,000,000

Shareholders’ Equity (Deficit):

Preference shares, $0.0001 par value; 5,000,000 shares authorized; none issued or outstanding

Class A ordinary shares, $0.0001 par value; 500,000,000 shares authorized; no non-redeemable shares issued and outstanding at December 31, 2021 and 2020

Class B ordinary shares, $0.0001 par value; 50,000,000 shares authorized; 10,350,000 shares issued and outstanding at December 31, 2021 and 2020(1)

1,035

1,035

1,035

Additional paid-in capital

23,965

Accumulated deficit

(21,455,236)

(32,419,614)

(12,681)

Total shareholders’ equity (deficit)

(21,454,201

(32,418,579)

12,319

Total Liabilities, Class A Ordinary shares Subject to Possible Redemption and Shareholders’ Equity (Deficit)

$

414,889,210

$

414,750,109

$

463,162

The December 31, 2020 amount included up to 1,350,000 Class B ordinary shares subject to forfeiture if the over-allotment option was not exercised in full or in part by the underwriters. On February 9, 2021, the full amount of the over-allotment was exercised resulting in no forfeiture of shares.

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Table of Contents

SELECTED HISTORICAL FINANCIAL INFORMATION OF DIACARTA

The following table sets forth selected historical financial information derived from DiaCarta’s unaudited financial statements as of and for the six months ended June 30, 2022, and DiaCarta’s audited financial statements as of and for the year ended December 31, 2021 and for the year ended December 31, 2020, each of which is included elsewhere in this proxy statement / prospectus. Such financial information should be read in conjunction with the audited and unaudited financial statements and related notes included elsewhere in this proxy statement / prospectus.

The historical results presented below are not necessarily indicative of the results to be expected for any future period. You should read the following summary financial information in conjunction with the section entitled “DiaCarta’s Management’s Discussion and Analysis of Financial Condition and Results of Operations” and HH&L’s financial statements and the related notes appearing elsewhere in this proxy statement / prospectus.

    

For the Six months 

    

For the Year 

    

For the Year 

 

Ended

Ended

Ended

 

June 30, 2022

December 31, 2021

December 31, 2020

 

Statement of Operations Data:

 

  

 

  

 

  

Revenues

$

14,522,296

$

41,501,568

$

14,445,079

Cost of Revenues

 

7,677,459

 

13,426,619

 

8,629,681

Gross Profit

 

6,844,837

 

28,074,949

 

5,815,398

Operating Expenses:

 

  

 

  

 

  

Selling and marketing expenses

 

1,013,467

 

1,820,038

 

1,182,573

General and administrative expenses

 

2,616,775

 

3,824,924

 

2,566,119

Research and development expenses

 

3,060,664

 

5,179,766