Matthew Scott Harris - Jan 31, 2023 Form 4 Insider Report for Altimmune, Inc. (ALT)

Role: Chief Medical Officer
Signature: /s/ Richard Eisenstadt, as Attorney-in-Fact
Stock symbol: ALT
Transactions as of: Jan 31, 2023
Transactions value $: -$16,852
Form type: 4
Date filed: 2/2/2023, 04:10 PM
Previous filing: Feb 1, 2023
Next filing: Feb 6, 2023

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	ALT	Common Stock, par value $0.0001	Award	$13.2K	+1.3K	+10.27%	$10.21	13.9K	Jan 31, 2023	Direct	F1, F2
transaction	ALT	Common Stock, par value $0.0001	Options Exercise	$0	+6.17K	+44.31%	$0.00	20.1K	Feb 1, 2023	Direct	F3
transaction	ALT	Common Stock, par value $0.0001	Tax liability	-$30.1K	-2.18K	-10.87%	$13.78	17.9K	Feb 1, 2023	Direct	F4

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	-6.17K	-33.33%	$0.00	12.3K	Feb 1, 2023	Common Stock, par value $0.0001	6.17K		Direct	F3, F5

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

Explanation of Responses:

Id	Content
F1	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, 2022 through January 31, 2023.
F2	In accordance with the ESPP, these shares were purchased based on 85% of the opening price of the issuer's common stock on August 1, 2022.
F3	Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Common Stock, par value $0.0001, when vested.
F4	Vesting transaction: Shares surrendered to the Issuer solely to cover taxes associated with vesting of RSUs.
F5	The RSUs become vested in substantially equal annual installments over the 4 years following February 1, 2021, subject to the reporting person's continued service through the applicable vesting date, and have no expiration date.