A Long-Term Extension Study to Evaluate the Immunogenicity and Safety of Cytomegalovirus (CMV) mRNA-1647 Vaccine
← catalyst calendarSponsored by ModernaTX, Inc. (industry) · MRNA — their whole pipeline →.
Phase
Phase 2
Status
Completed
Study type
Interventional
Design
Non randomized · None · Prevention
Enrollment
135actual
Sites
7
Country
United States
Every value on this page is a field the sponsor filed with ClinicalTrials.gov, reproduced. Dates are their own estimates, revised as a study runs, unless the registry marks them actual. sources →
Source: ClinicalTrials.gov, retrieved 2026-08-19
Dates
each axis at the precision it was filed, with the registry's own basis| Date | Filed | Basis | What it is |
|---|---|---|---|
| Start | 2021-06-18 | actual | When the study began enrolling |
| Primary completion | 2026-01-19 | actual | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | 2026-01-19 | actual | The whole study's end, after follow-up |
| First posted | 2021-07-26 | actual | When this record first appeared on the registry |
| Results posted | — | When the sponsor posted results to the registry | |
| Record updated | 2026-02-02 | actual | The sponsor's own last edit to this record — every projection above is as current as this date |
What it studies
Condition
- Cytomegalovirus Infection
Interventions
- Biological: mRNA-1647
- Other: mRNA-1647
Primary outcomes
what the primary-completion date above is the date OFPrimary Extension Phase: Geometric Mean Titers (GMTs) of Antigen-Specific Neutralizing Antibody (nAb) and Binding Antibody (bAb)
measured Up to 3 years
BP: GMTs of Antigen-Specific nAb and bAb
measured BP Month 0, BP Month 1, BP Month 3, BP Month 6, and BP Month 12
BP: Number of Participants with Solicited Adverse Reactions (ARs)
measured Up to BP Day 7 (7 days after BP vaccination)
BP: Number of Participants with Unsolicited Adverse Events (AEs)
measured Up to BP Day 28 (28 days after BP vaccination)
BP: Number of Participants with Medically-Attended AEs (MAAEs)
measured Up to BP Month 6 (6 months after BP vaccination)
BP: Number of Participants with Adverse Events of Special Interest (AESIs), Serious Adverse Events (SAEs), and AEs Leading to Discontinuation of Study
measured Up to BP Month 12
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