M. Scot Roberts - 25 Jan 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: 25 Jan 2026
Net transactions value: -$24,052
Form type: 4
Filing time: 27 Jan 2026, 07:00:04 UTC
Previous filing: 04 Aug 2025
Next filing: 29 Jan 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 Jan 2026	0001705905

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	ALT	Common Stock, par value $0.0001	Options Exercise	$0	+14,600	+20%	$0.000000	88,666	25 Jan 2026	Direct	F1
transaction	ALT	Common Stock, par value $0.0001	Tax liability	$24,052	-4,373	-4.9%	$5.50	84,293	25 Jan 2026	Direct	F2

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	Restricted Stock Units	Options Exercise	$0	-14,600	-33%	$0.000000	29,200	25 Jan 2026	Common Stock, par value $0.0001	14,600		Direct	F1, F3

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

Explanation of Responses:

Id	Content
F1	Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Common Stock, par value $0.0001, when vested.
F2	Vesting transaction: Shares surrendered to the Issuer solely to cover taxes associated with vesting of RSUs.
F3	The RSUs vest in substantially equal annual installments over the 4 years following January 25, 2024, subject to the reporting person's continued service through the applicable vesting date, and have no expiration date.