Altimmune, Inc. — Director's Dealing 2025

Oct 3, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Altimmune, Inc. (ALT)
CIK: 0001326190
Period of Report: 2025-10-01

Reporting Person: WEAVER GREGORY L (Chief Financial Officer)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-10-01	Stock Options (option to buy)	$3.87	A	166800	Acquired	2035-10-01	Common Stock, par value $0.0001 (166800)	Direct
2025-10-01	Restricted Stock Units	$	A	57900	Acquired		Common Stock, par value $0.0001 (57900)	Direct

Footnotes

F1: The shares underlying the option become vested and exercisable over four (4) years with 25% of the shares vesting on October 1, 2026, with the remainder vesting in equal monthly installments for the following thirty-six (36) months, subject to the reporting person's continued service on each applicable vesting date.

F2: Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Common Stock, par value $0.0001, when vested

F3: The RSUs become vested over four (4) years with 25% of the shares vesting October 1, 2026, with the remainder vesting in equal annual installments for the following three (3) years, subject to the reporting person's continued service through the applicable vesting date, and have no expiration date.