United States securities and exchange commission logo January 31, 2022 Steven T. Worland Chief Executive Officer eFFECTOR Therapeutics, Inc. 142 North Cedros Avenue, Suite B Solana Beach, California 92075 Re: eFFECTOR Therapeutics, Inc. Registration Statement on Form S-1 Filed January 25, 2022 File No. 333-262339 Dear Mr. Worland: 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 Jordan Nimitz at 202-551-5831 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences