A Study to Evaluate the Immunogenicity and Safety of mRNA-1283 COVID-19 Variant-containing Formulations
← catalyst calendarSponsored by ModernaTX, Inc. (industry) · MRNA — their whole pipeline →.
Phase
Phase 4
Status
Completed
Study type
Interventional
Design
Na · None · Prevention
Enrollment
832actual
Sites
5
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 | 2025-07-21 | actual | When the study began enrolling |
| Primary completion | 2026-06-16 | actual | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | 2026-06-16 | actual | The whole study's end, after follow-up |
| First posted | 2025-07-28 | actual | When this record first appeared on the registry |
| Results posted | — | When the sponsor posted results to the registry | |
| Record updated | 2026-07-07 | actual | The sponsor's own last edit to this record — every projection above is as current as this date |
What it studies
Condition
- COVID-19
Intervention
- Biological: mRNA-1283.251 Variant-containing Formulation — also filed as mNEXSPIKE®
Primary outcomes
what the primary-completion date above is the date OFSubprotocol 1: Part A - Geometric Mean (GM) Value of Neutralizing Antibody (nAb) Against Vaccine-matched COVID-19 Variants
measured Day 29
Subprotocol 1: Part A - Geometric Mean Fold Rise (GMFR) of nAb Against Vaccine-matched COVID-19 Variants
measured Baseline to Day 29
Subprotocol 1: Part B - GMFR of nAb Against Vaccine-matched COVID-19 Variants
measured Baseline to Day 29
Subprotocol 1: Part A - Seroresponse Rate (SRR) of nAb Against Vaccine-matched COVID-19 Variants
measured Baseline to Day 29
Permalink · MRNA's whole pipeline · Catalyst calendar · Every registered study · What changed