UNITED STATES SECURITIES AND EXCHANGE COMMISSION For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-41200 VIGIL NEUROSCIENCE, INC. (Exact name of Registrant as specified in its Charter) Delaware 85-1880494 Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 (State or other jurisdictio ...

Exhibit 99.1 Vigil Neuroscience Reports Fourth Quarter and Full Year 2023 Financial Results and Provides Business Update – Reported positive interim data from Phase 2 IGNITE proof-of-concept clinical trial evaluating iluzanebart (VGL101) for treatment of ALSP; - Enrollment for IGNITE trial completed with 20 patients enrolled; Next data readout planned for Q3 2024 – – Phase 1 healthy volunteer clinical trial evaluating VG-3927 ongoing; Interim data analysis on track for mid-2024 – – Appointed Biotech Industr ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ___________________ to ___________________ Commission File Number 001-41200 VIGIL NEUROSCIENCE, INC. (Exact name of Registrant as specified in its Charter ...

Washington, D.C. 20549 UNITED STATES SECURITIES AND EXCHANGE COMMISSION FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ___________________ to ___________________ Commission File Number 001-41200 VIGIL NEUROSCIENCE, INC. (Exact name of Registrant as specified in its Charter) (St ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ___________________ to ___________________ Commission File Number 001-41200 VIGIL NEUROSCIENCE, INC. (Exact name of Registrant as specified in its Charter) (S ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-41200 VIGIL NEUROSCIENCE, INC. (Exact name of Registrant as specified in its Charter) Delaware 85-1880494 (State or other jurisdictio ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ___________________ to ___________________ Commission File Number 001-41200 VIGIL NEUROSCIENCE, INC. (Exact name of Registrant as specified in its Charter ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ___________________ to ___________________ Commission File Number 001-41200 VIGIL NEUROSCIENCE, INC. (Exact name of Registrant as specified in its Charter) Del ...

Vigil Neuroscience Corporate Presentation June 2022 NEURO vigilant for you™ © Vigil Neuroscience, Inc. 2022. All rights reserved. FORWARD-LOOKING STATEMENTS This presentation contains "forward-looking statements," which are made pursuant to the safe harbor provisions of the federal securities laws, including the Private Securities Litigation Reform Act of 1995. Any statements that are not statements of historical fact may be deemed to be forward-looking statements. Such statements may contain words such as ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ___________________ to ___________________ Commission File Number 001-41200 VIGIL NEUROSCIENCE, INC. (Exact name of Registrant as specified in its Charter) De ...