CI

At a glance

ClinicalIndex Comparison Record
Phase 3Completed· 13,553 enrolled
Drug / intervention
mRNA-1283.222 +3 morebiological
Likely dose
Not stated in record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT05815498
NCT05815498Phase 3Completed
CompareCT.gov

A Randomized, Observer-Blind, Active-Controlled Phase 3 Study to Investigate the Safety, Immunogenicity, and Relative Vaccine Efficacy of mRNA-1283 Compared With mRNA-1273 in Participants Aged ≥12 Years for the Prevention of COVID-19

ModernaTX, Inc.·interventional·Posted Apr 18, 2023·Updated May 1, 2026

In Brief

A Phase 3 clinical trial evaluating mRNA-1283.222, mRNA-1273.222, and 2 other interventions for COVID-19. Completed, enrolled 13,553 participants across 230 sites in 4 countries.

Detailed Summary

The purpose of this study (Part 1 and Part 2) is to evaluate the relative vaccine efficacy (rVE), safety, reactogenicity, and immunogenicity of mRNA-1283.222 versus mRNA-1273.222 (Part 1) and mRNA-1283.815 versus mRNA-1273.815 (Part 2).

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
ConditionsCOVID-19
CountriesCanada, Japan, United Kingdom, United States
Collaborators--

Timeline

Phase 3CompletedFinished
202420252026
First PostedApr 18, 2023
Enrollment StartMar 28, 2023
Primary CompletionApr 12, 2025
TodayJul 2, 2026
Enrollment to primary: 2.0 yearsPosted 3.2 years ago

Interventions

mRNA-1283.222biological

Sterile liquid for injection

mRNA-1273.222biological

Sterile liquid for injection

mRNA-1283.815biological

Sterile liquid for injection

mRNA-1273.815biological

Sterile liquid for injection