M. Scot Roberts - 27 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: 27 Jan 2026
Net transactions value: -$29,343
Form type: 4
Filing time: 29 Jan 2026, 16:05:07 UTC
Previous filing: 27 Jan 2026
Next 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	29 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	+15,850	+19%	$0.000000	100,143	27 Jan 2026	Direct	F1
transaction	ALT	Common Stock, par value $0.0001	Tax liability	$29,343	-4,748	-4.7%	$6.18	95,395	27 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	-15,850	-25%	$0.000000	47,550	27 Jan 2026	Common Stock, par value $0.0001	15,850		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 27, 2025, subject to the reporting person's continued service through the applicable vesting date, and have no expiration date.