X0306 4 2022-06-23 0 0001828522 eFFECTOR Therapeutics, Inc. EFTR 0001709976 Gallagher Brian M. Jr. C/O EFFECTOR THERAPEUTICS, INC. 142 NORTH CEDROS AVENUE, SUITE B SOLANA BEACH CA 92075 1 0 0 0 Common Stock 2022-06-23 4 P 0 30000 1.59 A 30000 D The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $1.49 to $1.69. The Reporting Person undertakes to provide the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote. /s/ Michael Byrnes, Attorney-in-Fact for Brian M. Gallagher, Jr. 2022-06-27