X0306 4 2022-06-10 0 0001786255 Icosavax, Inc. ICVX 0001493023 Veneman Ann M C/O ICOSAVAX, INC. 1930 BOREN AVE., SUITE 1000 SEATTLE WA 98101 1 0 0 0 Common Stock 2022-06-10 4 A 0 5543 0.00 A 14043 D Stock Option (Right to Buy) 6.25 2022-06-10 4 A 0 22278 0.00 A 2032-06-09 Common Stock 22278 22278 D Represents restricted stock units ("RSUs") which will vest on the first to occur of (A) the first anniversary of the date of grant or (B) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continuous service on the board of directors of the Issuer through such vesting date. Each RSU represents a contingent right to receive one share of common stock of the Issuer and the RSUs have no expiration date. 1/12th of the total number of shares of common stock subject to the option vest monthly following June 10, 2022, the vesting commencement date, provided if the next occurring annual meeting of the Issuer's stockholders occurs prior to the full vesting of the option, any remaining options will vest on the date of such annual meeting, subject to the Reporting Person's continuous service on the board of directors of the Issuer through such vesting date. /s/ Elizabeth Bekiroglu, Attorney-in-Fact for Ann M. Veneman 2022-06-14