Altimmune awards Menziuso 84,546 stock options

Both equity awards have four-year vesting schedules that depend on continued service at the applicable vesting dates.

Rhea-AI Filing Summary

Altimmune, Inc. Principal Accounting Officer Richard Thomas Menziuso received 84,546 stock options and 36,234 restricted stock units on October 1, 2026. The options have a $2.76 exercise price. Both awards vest over four years, subject to his continued service on applicable vesting dates.

Insider Trade Summary

Grant/Award: 120,780 shares

Grant/Award 2 txns

Insider MENZIUSO RICHARD THOMAS

Role Principal Accounting Officer

Type	Security	Shares	Price	Value
Grant/Award	Stock Options (option to buy) F1	84,546	$0.00	$0.00
Grant/Award	Restricted Stock Units F2, F3	36,234	$0.00	$0.00

Holdings After Transaction: Stock Options (option to buy) — 84,546 contracts (Direct); Restricted Stock Units — 36,234 contracts (Direct)

Footnotes (3)

1. F1. The shares underlying the option become vested and exercisable over four (4) years with 25% of the shares vesting on October 1, 2027, with the remainder vesting in equal monthly installments for the following thirty-six (36) months, subject to the reporting person's continued service on each applicable vesting date.
2. F2. Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Common Stock, par value $0.0001, when vested.
3. F3. The RSUs become vested over four (4) years with 25% of the shares vesting on October 1, 2027, with the remainder vesting in equal annual installments for the following three (3) years, subject to the reporting person's continued service through the applicable vesting date, and have no expiration dat.

Key Figures

Stock options awarded: 84,546 options Option exercise price: $2.76 per share Restricted stock units awarded: 36,234 units +1 more

4 metrics

Stock options awarded 84,546 options Awarded October 1, 2026

Option exercise price $2.76 per share Options awarded October 1, 2026

Restricted stock units awarded 36,234 units Awarded October 1, 2026

Vesting period Four years Both awards, subject to continued service on applicable vesting dates

Key Terms

Restricted Stock Units, contingent right, vested and exercisable

3 terms

Restricted Stock Units technical

"Each Restricted Stock Unit represents a contingent right to receive one share"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

contingent right technical

"a contingent right to receive one share of Common Stock"

vested and exercisable technical

"The shares underlying the option become vested and exercisable over four years"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What equity awards did ALT's principal accounting officer receive?

Richard Thomas Menziuso received 84,546 stock options and 36,234 restricted stock units on October 1, 2026. The options have a $2.76 exercise price.

When do ALT's October 2026 options and restricted stock units vest?

For both awards, 25% vests on October 1, 2027, subject to continued service. The remaining options vest in equal monthly installments over the following 36 months; the remaining restricted stock units vest in equal annual installments over the following three years.

What does each ALT restricted stock unit represent?

Each restricted stock unit represents a contingent right to receive one share of common stock when vested.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 10/02/2026 - 04:18 PM Accepted by SEC EDGAR 10/02/2026 - 04:17 PM Learn about SEC filing dates

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).

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^*

MENZIUSO RICHARD THOMAS

(Last) (First) (Middle)

910 CLOPPER ROAD

SUITE 201S

(Street)

GAITHERSBURG MARYLAND 20878

(City) (State) (Zip)

UNITED STATES

(Country)

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

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
10/01/2026

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

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

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

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

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)	$2.76	10/01/2026		A		84,546		(1)	10/01/2036	Common Stock, par value $0.0001	84,546	$0	84,546	D
Restricted Stock Units	(2)	10/01/2026		A		36,234		(3)	(3)	Common Stock, par value $0.0001	36,234	$0	36,234	D

Explanation of Responses:

1. The shares underlying the option become vested and exercisable over four (4) years with 25% of the shares vesting on October 1, 2027, with the remainder vesting in equal monthly installments for the following thirty-six (36) months, subject to the reporting person's continued service on each applicable vesting date.

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

3. The RSUs become vested over four (4) years with 25% of the shares vesting on October 1, 2027, with the remainder vesting in equal annual installments for the following three (3) years, subject to the reporting person's continued service through the applicable vesting date, and have no expiration dat.

	/s/ Gregory Weaver, as Attorney-in-Fact	10/02/2026
	** 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).
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.
* Form 4: SEC 1474 (03-26)