X0306 4 2023-02-13 0 0001786255 Icosavax, Inc. ICVX 0001874021 Kanesa-thasan Niranjan C/O ICOSAVAX, INC. 1930 BOREN AVE., SUITE 1000 SEATTLE WA 98101 0 1 0 0 Chief Medical Officer Common Stock 2023-02-13 4 S 0 1794 10.6926 D 239187 D Represents shares withheld by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person to cover the applicable withholding taxes upon settlement of restricted stock units issued to the Reporting Person. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $10.41 to $11.02. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. /s/ Elizabeth Bekiroglu, Attorney-in-Fact 2023-02-15