Altimmune (ALT) director reports RSU vesting and ESPP share buy

Rhea-AI Filing Summary

Altimmune director Vipin K. Garg reported multiple equity transactions. On January 30, 2026, 26,775 Restricted Stock Units converted into an equal number of common shares at $0 exercise price as part of a vesting event. In connection with this vesting, 11,632 shares were surrendered to Altimmune to cover taxes at a price of $5.60 per share. On January 31, 2026, Garg acquired 6,926 additional common shares through the company’s 2019 Employee Stock Purchase Plan at $3.07 per share, equal to 85% of the August 1, 2025 closing price. After these transactions, Garg directly held 424,519 shares of common stock and 26,775 RSUs.

Insider Trade Summary

26,775 shares exercised/converted

Mixed 4 txns

Insider Garg Vipin K

Role Director

Type	Security	Shares	Price	Value
Grant/Award	Common Stock, par value $0.0001	6,926	$3.07	$21K
Exercise	Restricted Stock Units	26,775	$0.00	--
Exercise	Common Stock, par value $0.0001	26,775	$0.00	--
Tax Withholding	Common Stock, par value $0.0001	11,632	$5.60	$65K

Holdings After Transaction: Common Stock, par value $0.0001 — 424,519 shares (Direct); Restricted Stock Units — 26,775 shares (Direct)

Footnotes (1)

1. Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Common Stock, par value $0.0001, when vested. Vesting transaction: Shares surrendered to the Issuer solely to cover taxes associated with vesting of RSUs. 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 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 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.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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X

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Garg Vipin K

(Last) (First) (Middle)

910 CLOPPER ROAD

SUITE 201S

(Street)

GAITHERSBURG MD 20878

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Altimmune, Inc. [ ALT ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
01/30/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, par value $0.0001	01/30/2026		M		26,775	A	$0(1)	429,225	D
Common Stock, par value $0.0001	01/30/2026		F(2)		11,632	D	$5.6	417,593	D
Common Stock, par value $0.0001	01/31/2026		A(3)		6,926	A	$3.07(4)	424,519	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Stock Units	(1)	01/30/2026		M			26,775	(5)	(5)	Common Stock, par value $0.0001	26,775	$0	26,775	D

Explanation of Responses:

1. Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Common Stock, par value $0.0001, when vested.

2. Vesting transaction: Shares surrendered to the Issuer solely to cover taxes associated with vesting of RSUs.

3. 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

4. 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

5. 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.

	/s/ Gregory Weaver, as Attorney-in-Fact	02/02/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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FAQ

What insider transactions did Altimmune (ALT) director Vipin Garg report?

Altimmune director Vipin Garg reported RSU vesting into 26,775 common shares, a tax withholding of 11,632 shares, and the purchase of 6,926 shares through the company’s 2019 Employee Stock Purchase Plan.

How many Altimmune (ALT) shares does Vipin Garg own after these transactions?

After the reported transactions, Vipin Garg directly beneficially owned 424,519 shares of Altimmune common stock, plus 26,775 Restricted Stock Units that represent rights to receive an equal number of common shares upon future vesting.

What is the nature of the RSU transaction reported for Altimmune (ALT)?

The Form 4 shows 26,775 Restricted Stock Units converting into Altimmune common shares at a zero exercise price, as part of a scheduled vesting event under Garg’s equity compensation, with shares then surrendered to cover associated tax obligations.

Why were 11,632 Altimmune (ALT) shares surrendered by Vipin Garg?

The filing explains that 11,632 shares were surrendered back to Altimmune solely to cover taxes tied to RSU vesting. This is a common mechanism where part of vested shares are withheld instead of paying cash for tax liabilities.

How did Vipin Garg acquire additional Altimmune (ALT) shares through the ESPP?

Garg purchased 6,926 Altimmune shares under the 2019 Employee Stock Purchase Plan for the period August 1, 2025 through January 31, 2026, at $3.07 per share, equal to 85% of the stock’s August 1, 2025 closing price.