Catherine A. Sohn - 25 Sep 2025 Form 4 Insider Report for Altimmune, Inc. (ALT)

Role: Director
Signature: /s/ Gregory Weaver, as Attorney-in-Fact
Issuer symbol: ALT
Transactions as of: 25 Sep 2025
Net transactions value: $0
Form type: 4
Filing time: 29 Sep 2025, 16:21:00 UTC
Previous filing: 24 Sep 2025
Next filing: 05 Jan 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Sohn Catherine A.	Director	C/O ALTIMMUNE, INC., 910 CLOPPER ROAD,, SUITE 201S, GAITHERSBURG	/s/ Gregory Weaver, as Attorney-in-Fact	29 Sep 2025	0001555132

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	ALT	Stock Options (option to buy)	Award	$0	+48,800		$0.000000	48,800	25 Sep 2025	Common Stock, par value $0.0001	48,800	$3.92	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The shares underlying the option become vested and exercisable in substantially equal monthly installments over the 12 months following September 25, 2025, subject to the reporting person's continued service through the applicable vesting date.