Form 4 Filing for Altimmune, Inc.

Gregory L. Weaver, Chief Financial Officer of Altimmune, Inc., acquired 1753 shares of common stock through the Issuer's 2019 Employee Stock Purchase Plan (ESPP). The purchase occurred during the ESPP period from February 1, 2026, to July 31, 2026. The acquisition price was based on 85% of the closing stock price on July 31, 2026, amounting to $2.414 per share. Following this transaction, Mr. Weaver now holds 39,831 shares of common stock. The filing was signed on August 3, 2026.