X0206 3 2022-01-06 0 0001827087 Vigil Neuroscience, Inc. VIGL 0000318154 AMGEN INC ONE AMGEN CENTER DRIVE THOUSAND OAKS CA 91320 0 0 1 0 Series A Preferred Stock Common Stock 3206281 D These shares of Series A Preferred Stock are convertible into shares of the Issuer's common stock on a one-for-2.7732 basis and, upon completion of the Issuer's initial public offering, will automatically convert into the number of shares of the Issuer's common stock shown in Column 3. 10% beneficial ownership is calculated in accordance with SEC rules based on the number of shares of the Issuer's common stock outstanding on the date hereof and the conversion of only the reporting person's shares of preferred stock. /s/ Andrea A. Robinson, Vice President, Law, Governance and Securities & Assistant Secretary 2022-01-06