ALT Form 4: Director gift disclosed, 48,800-share option issued at $3.92

Rhea-AI Filing Summary

Altimmune insider activity: Director John Gill reports three items: a previously made bona fide gift of 2,714 shares of common stock, a correction that he currently holds zero shares directly or indirectly, and an option award for 48,800 shares with an exercise price of $3.92. The option was granted on the reported transaction date and vests monthly over 12 months beginning after the grant, with an exercise term extending roughly ten years from the grant date. The filing clarifies prior reporting errors that overstated his direct holdings by 57 shares and documents that the shares underlying the option are exercisable upon vesting.

Positive

• Correction of prior overstatement improves accuracy of insider ownership records by removing an inadvertent 57‑share overstatement
• Bona fide gift of 2,714 shares was previously made and is disclosed
• Time‑based option award of 48,800 shares vests monthly over 12 months, aligning director incentives with company performance

Negative

• None.

Insights

Securities Analyst

TL;DR: Director received a standard time‑based option award; prior ownership overstatement was corrected and direct holdings are now reported as zero.

The 48,800 share option at a $3.92 exercise price appears structured for short‑term retention, vesting monthly over the 12 months following the grant date and exercisable for roughly ten years. That creates potential future dilution only if exercised and provides alignment between the director and shareholders if exercised at or below market price at exercise. The correction reducing previously reported direct shares to zero improves the accuracy of insider ownership records; the earlier 57‑share overstatement was immaterial but its correction increases disclosure integrity.

Corporate Governance Expert

TL;DR: Governance disclosure corrected an ownership overstatement and records a routine director option grant with standard vesting.

The filing demonstrates appropriate remedial disclosure by correcting an inadvertent overstatement of 57 shares, which supports transparency. The option award follows a common structure: time‑based vesting over 12 months and a multi‑year exercise window. From a governance perspective, the filing is routine and reinforces accurate Section 16 reporting; there is no indication of unusual acceleration, related‑party transfers, or amendment triggers disclosed in the form.

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

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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

1. Name and Address of Reporting Person^*

GILL JOHN

(Last) (First) (Middle)

C/O ALTIMMUNE, INC., 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)
09/25/2025

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	01/06/2022		G		2,714(1)	D	$0	0(2)	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
Stock Options (option to buy)	$3.92	09/25/2025		A		48,800		(3)	09/25/2035	Common Stock, par value $0.0001	48,800	$0.00	48,800	D

Explanation of Responses:

1. Represents a bona fide gift of 2,714 shares of common stock made on January 6, 2022.

2. Certain Section 16 reports previously filed by the reporting person inadvertently overstated the reporting person's direct common stock ownership by 57 shares. As of the date of this filing, the reporting person does not hold any shares of common stock directly or indirectly.

3. The shares underlying the option become vested and exercisable in substantially equal monthly installments over the 12 months following September 25, 2025, subject to the reporting person's continued service through the applicable vesting date.

Remarks:

Exhibit 24 - Power of Attorney

	/s/ Gregory Weaver, as Attorney-in-Fact	09/29/2025
	** 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transactions did Altimmune (ALT) report for John Gill?

The filing reports a prior gift of 2,714 shares, a correction that the reporting person now holds 0 shares, and an option grant for 48,800 shares at a $3.92 exercise price.

What are the terms of the option granted to the director?

The option covers 48,800 underlying shares with an exercise price of $3.92, vesting in substantially equal monthly installments over the 12 months following the grant and exercisable for about ten years.

Does the filing change the director's current ownership of Altimmune stock?

Yes; the filing states that, after correcting prior reports, the reporting person does not hold any shares directly or indirectly.

Was there an error corrected in prior Section 16 reports?

Yes; prior reports inadvertently overstated direct common stock ownership by 57 shares, and this filing corrects that overstatement.

Does the filing show immediate dilution from the option grant?

No immediate dilution is recorded; the option represents potential future dilution only if and when the option is exercised after vesting.