Altimmune (ALT) awards 48,800 stock options to director Catherine Sohn

Rhea-AI Filing Summary

Altimmune, Inc. director Catherine A. Sohn received a grant of stock options as part of her non-employee director compensation. She was awarded 48,800 stock options to buy common stock at an exercise price of $2.82 per share, with no cash paid at grant.

The options become vested and exercisable in substantially equal monthly installments over the 12 months following May 1, 2026, subject to her continued service. Any unexercised options expire on May 1, 2036, and her reported post-transaction holdings in this option grant are 48,800 options.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Sohn Catherine A.

Role null

Type	Security	Shares	Price	Value
Grant/Award	Stock Options (option to buy)	48,800	$0.00	--

Holdings After Transaction: Stock Options (option to buy) — 48,800 shares (Direct, null)

Footnotes (1)

1. The options were granted pursuant to the Company's non-employee director compensation policy. The shares underlying the option become vested and exercisable in substantially equal monthly installments over the 12 months following May 1, 2026, subject to the reporting person's continued service through the applicable vesting date.

Key Figures

Options granted: 48,800 options Exercise price: $2.82 per share Underlying shares: 48,800 shares +3 more

6 metrics

Options granted 48,800 options Grant to director Catherine A. Sohn

Exercise price $2.82 per share Stock options grant

Underlying shares 48,800 shares Common stock underlying options

Expiration date May 1, 2036 Option term endpoint

Vesting period 12 months Monthly vesting after May 1, 2026

Post-grant option holdings 48,800 options Total options following transaction

Key Terms

non-employee director compensation policy, stock options, vested and exercisable, exercise price

4 terms

non-employee director compensation policy financial

"The options were granted pursuant to the Company's non-employee director compensation policy."

stock options financial

"The options were granted pursuant to the Company's non-employee director compensation policy."

Stock options are agreements that give a person the right to buy or sell a company's stock at a specific price within a certain time frame. They are often used as a reward or incentive, similar to a coupon that can be used later if the stock price rises, allowing the holder to make a profit.

vested and exercisable financial

"The shares underlying the option become vested and exercisable in substantially equal monthly installments"

exercise price financial

"conversion_or_exercise_price": "2.8200""

The exercise price is the fixed amount at which you can buy or sell an asset, like a stock, when using an options contract. It matters because it helps determine whether exercising the option will be profitable or not, depending on the current market price. Think of it as the set price you agree on today to buy or sell later.

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

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^*

Sohn Catherine A.

(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)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/01/2026

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)(1)	$2.82	05/01/2026		A		48,800		(2)	05/01/2036	Common Stock, par value $0.0001	48,800	$0	48,800	D

Explanation of Responses:

1. The options were granted pursuant to the Company's non-employee director compensation policy.

2. The shares underlying the option become vested and exercisable in substantially equal monthly installments over the 12 months following May 1, 2026, subject to the reporting person's continued service through the applicable vesting date.

	/s/ Gregory Weaver, as Attorney-in-Fact	05/01/2026
	** 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)

FAQ

What did Altimmune (ALT) director Catherine A. Sohn receive in this Form 4 filing?

Catherine A. Sohn received a grant of 48,800 stock options to buy Altimmune common stock. The grant is compensation under the non-employee director policy, not an open-market purchase, and gives her the right to buy shares at a fixed exercise price.

What is the exercise price of the stock options granted to the Altimmune (ALT) director?

The stock options granted to Catherine A. Sohn have an exercise price of $2.82 per share. This means she can choose to buy Altimmune common stock at $2.82, regardless of the market price at the time she exercises, once the options vest.

How and when do Catherine A. Sohn’s Altimmune (ALT) stock options vest?

The 48,800 stock options vest in substantially equal monthly installments over the 12 months following May 1, 2026. Vesting is conditioned on her continued service as a director through each applicable vesting date before the options become exercisable.

When do the Altimmune (ALT) stock options granted to the director expire?

The stock options granted to Catherine A. Sohn expire on May 1, 2036. After that expiration date, any unexercised options will lapse and no longer allow her to purchase Altimmune common stock at the $2.82 exercise price.

How many Altimmune (ALT) stock options does the director hold after this grant?

Following this grant, Catherine A. Sohn holds 48,800 stock options from this award, as reported in the filing. These options relate to the same number of underlying shares of common stock and are subject to the stated vesting and expiration terms.