United States securities and exchange commission logo August 23, 2022 Adam Simpson Chief Executive Officer Icosavax, Inc. 1930 Boren Avenue, Suite 1000 Seattle, WA 98101 Re: Icosavax, Inc. Registration Statement on Form S-3 Filed August 16, 2022 File No. 333-266894 Dear Mr. Simpson: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 460 and 461 regarding requests for acceleration. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Please contact Doris Stacey Gama at 202-551-3188 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Cheston Larson, Esq.