AIM ImmunoTech Inc.美国招股说明书（2026年4月10日版）

AMENDMENT NO. 1 DATED APRIL 10, 2026To Prospectus Supplement dated October 30, 2025(To Prospectus Dated July 3, 2025) Up to $3,409,174AIM IMMUNOTECH INC. This prospectus supplement supplements, modifies and supersedes, only to the extent indicated herein, certain informationcontained in our prospectus supplement dated October 30, 2025, which together with the accompanying prospectus dated July 3, 2025contained in our Registration Statement on Form S-3 (Registration No. 333-286319), we refer to as the prospectus, relating to theoffering, issuance and sale of shares of our common stock, par value $0.001 per share, from time to time through our sales agent, This prospectus supplement should be read in conjunction with, is not complete without, and may not be delivered or utilizedexcept in connection with, the prospectus, including all supplements thereto and documents incorporated by reference therein. If thereis any inconsistency between the information in the prospectus and this prospectus supplement, you should rely on the information in As of April 10, 2026, the aggregate market value of our outstanding common stock held by non-affiliates, or the public float,was approximately $10,227,521, which was calculated based on 8,182,017 shares of our outstanding common stock held by non-affiliates at a price of $1.25 per share, the closing price of our common stock on February 13, 2026. Pursuant to General InstructionI.B.6 of Form S-3, in no event will we sell shares pursuant to this prospectus supplement with a value of more than one-third of theaggregate market value of our common stock held by non-affiliates in any 12-month period, or $3,409,174. As of the date of thisprospectus supplement, we have sold approximately $2,288,758.60 of securities pursuant to General Instruction I.B.6 of Form S-3during the 12 calendar months prior to, and including, the date of this prospectus supplement, and are therefore eligible to sell up to an We are filing this prospectus supplement to supplement and amend, as of April 10, 2026, the prospectus, as supplemented, toincrease the maximum aggregate offering price of our common stock that may be offered, issued and sold under the prospectus, as Our common stock is traded on the NYSE American under the symbol “AIM.” On April 9, 2026, the last reported sale priceof our common stock was $0.5180 per share. Sales of our common stock, if any, under this prospectus supplement and accompanying prospectus may be made in salesdeemed to be “at the market offerings” as defined in Rule 415 under the Securities Act of 1933, as amended, or the Securities Act.Maxim is not required to sell any specific number or dollar amount of securities but will act as a sales agent using commercially The compensation to Maxim for sales of common stock sold pursuant to the EDA will be up to 3.0% of the gross proceeds ofany shares of common stock sold under the EDA. In connection with the sale of the common stock on our behalf, Maxim will bedeemed to be an “underwriter” within the meaning of the Securities Act and the compensation of Maxim will be deemed to be Investing in our common stock involves a high degree of risk. See “Risk Factors” beginning on page S-7 of the prospectussupplement dated October 30, 2025, page 3 of the accompanying prospectus and under similar headings in the documents Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of thesesecurities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any Maxim Group LLC The date of this prospectus supplement is April 10, 2026