X0306 4 2022-01-20 0 0001828522 eFFECTOR Therapeutics, Inc. EFTR 0001879012 Patel Premal C/O EFFECTOR THERAPEUTICS, INC. 142 NORTH CEDROS AVENUE, SUITE B SOLANA BEACH CA 92075 0 1 0 0 Chief Medical Officer Stock Option (Right to Buy) 6.65 2022-01-20 4 A 0 150000 0.00 A 2032-01-19 Common Stock 150000 150000 D 1/48th of the total number of shares subject to the options shall vest on each monthly anniversary of January 20, 2022 (the "Vesting Commencement Date"), subject to the Reporting Person's continuous service to the Issuer on each such vesting date, so that the options shall be fully vested on the fourth anniversary of the Vesting Commencement Date. /s/ Michael Byrnes, Attorney-in-Fact for Premal Patel 2022-01-24