M. Scot Roberts - 26 Feb 2026 Form 4 Insider Report for Altimmune, Inc. (ALT)

Role: Chief Scientific Officer
Signature: /s/ Gregory Weaver, as Attorney-in-Fact
Issuer symbol: ALT
Transactions as of: 26 Feb 2026
Net transactions value: $0
Form type: 4
Filing time: 27 Feb 2026, 16:10:07 UTC
Previous filing: 03 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Roberts M Scot	Chief Scientific Officer	910 CLOPPER ROAD, SUITE 201S, GAITHERSBURG	/s/ Gregory Weaver, as Attorney-in-Fact	27 Feb 2026	0001705905

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	+222,670		$0.000000	222,670	26 Feb 2026	Common Stock, par value $0.0001	222,670	$4.46	Direct	F1
transaction	ALT	Restricted Stock Units	Award	$0	+95,430		$0.000000	95,430	26 Feb 2026	Common Stock, par value $0.0001	95,430		Direct	F2, F3

* 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 over four (4) years with 25% of the shares vesting on February 26, 2027, 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 February 26, 2027, 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.