A Long-Term Extension Study to Evaluate the Immunogenicity and Safety of Cytomegalovirus (CMV) mRNA-1647 Vaccine

Summary

The main purpose of the extension phase of this study is to evaluate the longer-term immune persistence of mRNA-1647 vaccine administered to CMV-seronegative and CMV-seropositive adults who completed Study mRNA-1647-P202 (NCT04232280). For participants in the optional booster phase (BP), the main purpose is to evaluate the long-term immunogenicity and safety of the mRNA-1647 vaccine in both participants receiving a booster dose (BD) and those not receiving a BD, and to additionally evaluate the reactogenicity in participants receiving a BD.

Timeline

Start

2021-06-18

Primary completion

2026-01-19

Completion

2026-01-19

Drugs

Indications