A Study to Evaluate the Safety and Immunogenicity of the mRNA COVID-19 Vaccines in Healthy Children Between 6 Months to Less Than 6 Years of Age
← catalyst calendarSponsored by ModernaTX, Inc. (industry) · MRNA — their whole pipeline →.
Phase
Phase 3
Status
Completed
Study type
Interventional
Design
Non randomized · None · Prevention
Enrollment
1,807actual
Sites
74
Countries
Argentina, Chile, Colombia +4
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 | 2022-06-21 | actual | When the study began enrolling |
| Primary completion | 2025-10-20 | actual | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | 2025-10-20 | actual | The whole study's end, after follow-up |
| First posted | 2022-06-29 | actual | When this record first appeared on the registry |
| Results posted | — | When the sponsor posted results to the registry | |
| Record updated | 2025-11-26 | actual | The sponsor's own last edit to this record — every projection above is as current as this date |
What it studies
Condition
- SARS-CoV-2
Interventions
- Biological: mRNA-1273.214
- Biological: mRNA-1273.815
Primary outcomes
what the primary-completion date above is the date OFNumber of Participants with Solicited Local and Systemic Adverse Reactions (ARs)
measured Up to Day 8 (7 days post-vaccination)
Number of Participants with Unsolicited Adverse Events (AEs)
measured Up to Day 29 (28 days after each injection)
Number of Participants with Medically-Attended AEs (MAAEs)
measured Up to Day 394 (12 months after last dose)
Number of Participants with Serious AEs (SAEs)
measured Up to Day 394 (12 months after last dose)
Number of Participants with Adverse Events of Special Interest (AESI)
measured Up to Day 394 (12 months after last dose)
Number of Participants with AEs Leading to Withdrawal
measured Up to Day 394 (12 months after last dose)
Geometric Mean (GM) of the Serum Antibody (Ab) Level against Omicron BA.1 and Ancestral SARS-CoV-2 after mRNA-1273.214 Administration at Day 57
measured Day 57
GM of the Serum Ab Level against Omicron BA.1 and Ancestral SARS-CoV-2 after mRNA-1273.214 Administration at Day 29
measured Day 29
Seroresponse Rate (SRR) against Omicron BA.1 and Ancestral SARS-CoV-2 after mRNA-1273.214 Administration
measured Day 29
GM of the Serum Ab Level against Omicron XBB.1.5 after mRNA-1273.815 Administration
measured Up to Day 57
Publications
- PMID 38518789 — linked by the registry
Linked on the registry record. A “linked by the registry” entry is NLM's own automated PubMed match, not a claim by the sponsor that the paper reports this study.
Permalink · MRNA's whole pipeline · Catalyst calendar · Every registered study · What changed