X0306 4 2019-06-10 0 0001326190 Altimmune, Inc. ALT 0001742241 Brown William Michael C/O ALTIMMUNE, INC., 910 CLOPPER ROAD, SUITE 201S GAITHERSBURG MD 20878 0 1 0 0 Chief Financial Officer Stock Options (option to buy) 2.34 2019-06-10 4 A 0 50000 0.00 A 2029-06-10 Common Stock, par value $0.0001 50000 50000 D Twenty-five percent of the shares underlying the option become vested and exercisable on June 1, 2020 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following June 1, 2020, subject to the reporting person's continued service through the applicable vesting date. Exhibit 24 - Power of Attorney /s/ William M. Brown 2019-06-12