Sec Form 3 Filing - Shutterly Andrew @ Altimmune, Inc. - 2024-06-26

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Shutterly Andrew 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) See Remarks (Last) (First) (Middle) C/O ALTIMMUNE, INC., 910 CLOPPER ROAD, SUITE 201S 3. Date of Earliest Transaction (MM/DD/YY) 06/26/2024 (Street) GAITHERSBURG, MD20878 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 10,113 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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 of Derivative Security: 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 Option (Right to Buy) $ 7.05 ( 1 ) 03/17/2032 Common Stock, par value $0.0001 20,000 D Stock Option (Right to Buy) $ 12.88 ( 2 ) 01/30/2033 Common Stock, par value $0.0001 25,000 D Stock Option (Right to Buy) $ 4.48 ( 3 ) 05/22/2033 Common Stock, par value $0.0001 15,000 D Stock Option (Right to Buy) $ 9.28 ( 4 ) 01/25/2034 Common Stock, par value $0.0001 12,000 D Restricted Stock Units $ 0 ( 5 ) ( 5 ) Common Stock, par value $0.0001 11,250 D Restricted Stock Units $ 0 ( 6 ) ( 6 ) Common Stock, par value $0.0001 3,000 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Shutterly Andrew C/O ALTIMMUNE, INC. 910 CLOPPER ROAD, SUITE 201S GAITHERSBURG, MD20878 See Remarks Signatures /s/ Vipin K. Garg, as Attorney-in-Fact 07/01/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Twenty-five percent of the shares underlying the option became vested and exercisable on March 17, 2023 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following March 17, 2023, subject to the reporting person's continued service through the applicable vesting date. ( 2 )Twenty-five percent of the shares underlying the option became vested and exercisable on January 30, 2024 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 30, 2024, subject to the reporting person's continued service through the applicable vesting date. ( 3 )Twenty-five percent of the shares underlying the option became vested and exercisable on May 22, 2024 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following May 22, 2024, subject to the reporting person's continued service through the applicable vesting date. ( 4 )Twenty-five percent of the shares underlying the option become vested and exercisable on January 25, 2025 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 25, 2025, subject to the reporting person's continued service through the applicable vesting date. ( 5 )The RSUs will vest in equal annual installments of 3,750 shares on January 30, 2025, January 30, 2026 and January 30, 2027, subject to the reporting person's continued service through the applicable date, and have no expiration date. ( 6 )The RSUs become vested and exercisable over four 4 years with 25% of the shares vesting on January 25, 2025, with the remainder vesting in equal annual installments for the following three years, subject to the reporting person's continued service through the applicable date, and have no expiration date.

Remarks: Acting Chief Financial Officer. Exhibit 24 - Power of Attorney.

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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