X0206 3 2021-07-28 0 0001786255 Icosavax, Inc. ICVX 0001873839 Simpson Adam K. C/O ICOSAVAX, INC. 1616 EASTLAKE AVENUE E., SUITE 208 SEATTLE WA 98102 1 1 0 0 Chief Executive Officer Common Stock 781576 I By family trust Common Stock 4032 I By family trust Common Stock 4032 I By family trust Stock Option (Right to Buy) 0.83 2030-05-10 Common Stock 76634 D Stock Option (Right to Buy) 1.04 2031-01-28 Common Stock 512534 D Stock Option (Right to Buy) 5.90 2031-04-11 Common Stock 1347546 D Stock Option (Right to Buy) 15.00 2031-07-27 Common Stock 375000 D Includes 198,718 shares subject to repurchase by us, which are subject to vesting. 25% of the shares subject to the option vested on 2/21/2021, and 1/48th of the shares subject to the option vest monthly thereafter. 25% of the shares subject to the option will vest on 1/14/2022, and 1/48th of the shares subject to the option vest monthly thereafter. 25% of the shares subject to the option will vest on 3/19/2022, and 1/48th of the shares subject to the option vest monthly thereafter. 1/48th of the shares subject to the option vest monthly following July 28, 2021, the vesting commencement date. Exhibit List: Exhibit 24 - Power of Attorney /s/ Thomas Russo, Attorney-in Fact 2021-07-28