M. Scot Roberts - 30 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: 30 Jan 2026
Net transactions value: -$11,846
Form type: 4
Filing time: 03 Feb 2026, 16:15:42 UTC
Previous filing: 29 Jan 2026
Next filing: 27 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	03 Feb 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	+9,275	+9.7%	$0.000000	104,670	30 Jan 2026	Direct	F1
transaction	ALT	Common Stock, par value $0.0001	Tax liability	$16,010	-2,859	-2.7%	$5.60	101,811	30 Jan 2026	Direct	F2
transaction	ALT	Common Stock, par value $0.0001	Award	$17,091	+5,567	+5.5%	$3.07	107,378	31 Jan 2026	Direct	F3, F4
transaction	ALT	Common Stock, par value $0.0001	Options Exercise	$0	+7,775	+7.2%	$0.000000	115,153	02 Feb 2026	Direct	F1
transaction	ALT	Common Stock, par value $0.0001	Tax liability	$12,926	-2,329	-2%	$5.55	112,824	02 Feb 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	-9,275	-50%	$0.000000	9,275	30 Jan 2026	Common Stock, par value $0.0001	9,275		Direct	F1, F5
transaction	ALT	Restricted Stock Units	Options Exercise	$0	-7,775	-100%	$0.000000	0	02 Feb 2026	Common Stock, par value $0.0001	7,775		Direct	F1, F6

* 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	These shares were purchased due to participation by the reporting individual in the Issuer's 2019 Employee Stock Purchase Plan ("ESPP"). It pertains to the ESPP purchase period from August 1, 2025 through January 31, 2026.
F4	In accordance with the ESPP, these shares were purchased based on 85% of the closing price of the Issuer's common stock on August 1, 2025.
F5	The RSUs become vested in substantially equal annual installments over the 4 years following January 30, 2023, subject to the reporting person's continued service through the applicable vesting date, and have no expiration date.
F6	The RSUs become vested in substantially equal annual installments over the 4 years following February 2, 2022, subject to the reporting person's continued service through the applicable vesting date, and have no expiration date.