X0407 4 2023-06-07 0 0001827087 Vigil Neuroscience, Inc. VIGL 0001451612 Booth Bruce VIGIL NEUROSCIENCE, INC. 100 FORGE ROAD, SUITE 700 WATERTOWN MA 02472 1 0 0 0 0 Common Stock 4808896 I By Atlas Venture Fund XII, L.P. Common Stock 1027978 I By Atlas Venture Opportunity Fund I, L.P. Stock Option Grant (Right to Buy) 10.00 2023-06-07 4 A 0 13928 0.00 A 2033-06-07 Common Stock 13928 13928 D These shares are held directly by Atlas Venture Fund XII, L.P. ("Atlas Venture Fund XII"). The general partner of Atlas Venture Fund XII is Atlas Venture Associates XII, L.P. ("AVA XII LP"). Atlas Venture Associates XII, LLC ("AVA XII LLC") is the general partner of AVA XII LP. The Reporting Person is a member of AVA XII LLC and disclaims beneficial ownership of such securities held by Atlas Venture Fund XII, except to the extent of his pecuniary interest therein, if any. The shares are held directly by Atlas Venture Opportunity Fund I, L.P. ("Atlas Venture Opportunity Fund I"). The general partner of Atlas Venture Opportunity Fund I is Atlas Venture Associates Opportunity I, L.P. ("AVAO I LP"). Atlas Venture Associates Opportunity I, LLC ("AVAO I LLC") is the general partner of AVAO I LP. The Reporting Person is a member of AVAO I LLC and disclaims beneficial ownership of such securities held by Atlas Venture Opportunity Fund I, 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 7, 2024 and (ii) the next annual meeting of the Issuer's stockholders. The Reporting Person is a member of Atlas Venture Associates XII, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the option to Atlas Venture Life Science Advisors, LLC. As such, the Reporting Person disclaims beneficial ownership of the securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, except to the extent of his pecuniary interest therein, if any. /s/ Ommer Chohan, Attorney-in-Fact 2023-06-09