X0306 4 2022-06-09 0 0001827087 Vigil Neuroscience, Inc. VIGL 0001826967 Vitorovic Stefan VIGIL NEUROSCIENCE, INC. 1 BROADWAY, 7TH FLOOR, SUITE 07-300 CAMBRIDGE MA 02142 1 0 0 0 Common Stock 5004393 I By Vida Ventures III, L.P. Common Stock 11536 I By Vida Ventures III-A, .P. Stock Option Grant (Right to Buy) 3.10 2022-06-09 4 A 0 12155 0.00 A 2032-06-09 Common Stock 12155 12155 D The shares are held directly by Vida Ventures III, L.P. ("Vida III"). Vida Ventures GP III, L.L.C. ("Vida III GP") is the general partner of of Vida III. The Reporting Person is a managing member of Vida III GP and disclaims beneficial ownership of the shares held directly by Vida III, except to the extent of his pecuniary interest therein, if any. The shares are held directly by Vida Ventures III-A, L.P. ("Vida III-A"). Vida III GP is the general partner of of Vida III-A. The Reporting Person is a managing member of Vida III GP and disclaims beneficial ownership of the shares held directly by Vida III-A, except to the extent of his pecuniary interest therein, if any. The shares subject to this option shall vest and become exercisable upon the earlier to occur of (i) June 9, 2023 and (ii) the next annual meeting of the Issuer's stockholders. /s/ Jennifer Ziolkowski, Attorney-in-Fact 2022-06-13