HCW Biologics Inc.

BINDING TERM SHEET FOR CONVERSION OF SENIOR SECURED NOTES

HCW Biologics Inc. (the “Company”) and the undersigned holders (each, a “Noteholder”) of promissory notes of the Company are parties to (1) that certain Amended and Restated Senior Secured Note Purchase Agreement dated as of July 2, 2024, as amended (the “Note Purchase Agreement”), pursuant to which the Company issued to each Noteholder a Senior Secured Promissory Note representing each Noteholder’s investment in the Company (as amended, the “Notes”), (2) that certain Amended and Restated Pledge Agreement dated as of July 2, 2024 (the “Pledge Agreement”), and (3) that certain Amended and Restated Escrow Agreement dated as of July 2, 2024 (the “Escrow Agreement”). Capitalized terms used in this Term Sheet without further definition are used herein as defined in the Note Purchase Agreement.

Pursuant to Section 6 of the Note Purchase Agreement, the parties agreed to “negotiate in good faith terms and conditions for an amendment to [the Note Purchase Agreement]” under which the Notes would be converted into shares of the Company’s common stock, par value $0.0001 per share (“Common Stock”), following final resolution of the Arbitration and a bona fide equity financing with proceeds of at least $5.0 million. The Arbitration has been resolved and dismissed, and the Company completed a $6.9 million equity financing on November 18, 2024.

This Binding Term Sheet sets forth the principal terms upon which the Company and the Noteholders have agreed that the outstanding principal and accrued interest under the Notes will be converted to shares of Common Stock (the “Conversion”).

The parties agree that they will execute appropriate amendments to the Note Purchase Agreement, Notes, Pledge Agreement and Escrow Agreement (together, the “Amendment”) providing for such conversion in accordance with this Binding Term Sheet, such Amendment to be effective upon approval of the Conversion at a special meeting of the Company’s stockholders to be called and held as soon as commercially practicable after the execution of this Binding Term Sheet (“Stockholder Approval”).

ACCEPTED AND AGREED as of February 20, 2025:

Exhibit A

SCAN TO VIEW MATERIALS & VOTE HCW BIOLOGICS INC. 2929 N. COMMERCE PKWY MIRAMAR, FL 33025 VOTE BY INTERNET - www.proxyvote.com or scan the QR Barcode above Use the Internet to transmit your voting instructions and for electronic delivery of information. Vote by 11:59 P.M. ET on 03/30/2025 for shares held directly and by 11:59 P.M. ET on 03/26/2025 for shares held in a Plan. Have your proxy card in hand when you access the web site and follow the instructions to obtain your records and to create an electronic voting instruction form. During The Meeting - Go to www.virtualshareholdermeeting.com/HCWB2025SM You may attend the meeting via the Internet and vote during the meeting. Have the information that is printed in the box marked by the arrow available and follow the instructions. VOTE BY PHONE - 1-800-690-6903 Use any touch-tone telephone to transmit your voting instructions. Vote by 11:59 P.M. ET on 03/30/2025 for shares held directly and by 11:59 P.M. ET on 03/26/2025 for shares held in a Plan. Have your proxy card in hand when you call and then follow the instructions. VOTE BY MAIL Mark, sign and date your proxy card and return it in the postage-paid envelope we have provided or return it to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717. TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS: KEEP THIS PORTION FOR YOUR RECORDS THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED. DETACH AND RETURN THIS PORTION ONLY The Board of Directors recommends you vote FOR Proposals 1 and 2. For Against Abstain For Against Abstain 1. To approve an amendment to the Company’s Certificate of Incorporation on or before the one-year anniversary of the Special Meeting to implement reverse stock splits of the outstanding shares of our Common Stock in a range fromone-for-twenty (1:20) up toone-for-fifty (1:50), all as determined in the sole discretion of the Company’s Board of Directors. 2. To approve, for purposes of complying with Nasdaq Listing Rule 5635(d), the full issuance of shares of our Common Stock, or such lesser number of shares as the Board of Directors determines, pursuant to the Company’s Equity Line of Credit (as defined in the Proxy Statement (the “ELOC Proposal”)). The Board of Directors does not have a recommendation for voting on the following proposal: 3. To approve, for purposes of complying with Nasdaq Listing Rules 5635(c) and 5635(d), the issuance of shares of our Common Stock upon conversion of up to $6,905,000 of principal amount of Senior Secured Notes issued by the Company to certain investors therein, including certain officers, directors and stockholders of the Company, pursuant to the Principal Terms as defined in the Proxy Statement. NOTE: Such other business as may properly come before the meeting or any adjournment thereof. Please sign exactly as your name(s) appear(s) hereon. When signing as attorney, executor, administrator, or other fiduciary, please give full title as such. Joint owners should each sign personally. All holders must sign. If a corporation or partnership, please sign in full corporate or partnership name by authorized officer. Signature [PLEASE SIGN WITHIN BOX] Date Signature (Joint Owners) Date 0000660128_1 R1.0.0.2

Important Notice Regarding the Availability of Proxy Materials for the Special Meeting: The Special Proxy is available at www.proxyvote.com HCW BIOLOGICS INC. Special Meeting of Stockholders March 31, 2025 10:00 AM EST This proxy is solicited by the Board of Directors The Stockholder(s) hereby appoint(s) Dr. Hing C. Wong, Chief Executive Officer, and Rebecca Byam, Chief Financial Officer, or either of them, as proxies, each with the power to appoint (his/her) substitute, and hereby authorize(s) them to represent and to vote, as designated on the reverse side of this ballot, all of the shares of Common Stock of HCW BIOLOGICS INC. that the Stockholder(s) is/are entitled to vote at the Special Meeting of Stockholders to be held at 10:00 AM, EST on March 31, 2025, virtually at www.virtualshareholdermeeting.com/ HCWB2025SM, and any adjournment or postponement thereof. This proxy, when properly executed, will be voted in the manner directed herein. If no such direction is made, this proxy will be voted in accordance with the Board of Directors’ recommendations. Continued and to be signed on reverse side 0000660128_2 R1.0.0.2