A Study of mRNA-1345, an mRNA Vaccine Targeting Respiratory Syncytial Virus, in Children 2 to <18 Years of Age at High Risk of Respiratory Syncytial Virus
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Phase
Phase 2
Status
Completed
Study type
Interventional
Design
Randomized · Quadruple · Prevention
Enrollment
349actual
Sites
50
Countries
Panama, 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 | 2023-10-24 | actual | When the study began enrolling |
| Primary completion | 2025-06-27 | actual | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | 2025-06-27 | actual | The whole study's end, after follow-up |
| First posted | 2023-10-24 | actual | When this record first appeared on the registry |
| Results posted | 2026-08-18 | actual | When the sponsor posted results to the registry |
| Record updated | 2026-08-18 | actual | The sponsor's own last edit to this record — every projection above is as current as this date |
What it studies
Condition
- Respiratory Syncytial Virus
Interventions
- Biological: mRNA-1345
- Biological: Placebo
Primary outcomes
what the primary-completion date above is the date OFPart A (Cohorts 1 and 2): Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs)
measured Up to 7 days post-injection
Part A (Cohorts 1 and 2): Number of Participants With Unsolicited Adverse Events (AEs)
measured Up to 28 days post-injection
Part A (Cohorts 1 and 2): Number of Participants With Medically Attended AEs (MAAEs), Adverse Events of Special Interest (AESIs), Serious Adverse Events (SAEs), and AEs Leading to Study Discontinuation
measured Day 1 through end of Part A (Month 6)
Part B (Cohort 1): Number of Participants With RSV-RTD, Respiratory Syncytial Virus- Lower Respiratory Tract Disease (RSV-LRTD), Severe RSV-LRTD, Very Severe RSV-LRTD and RSV Hospitalization Classified by Clinical Assessment Team (CAT)
measured Day 1 through end of Part B (Month 6)
Posted documents
hosted by the registry — we link, never re-serveStudy Protocolposted 2024-10-02 · 1.5 MB · Prot_000.pdf
Statistical Analysis Planposted 2025-06-02 · 1.5 MB · SAP_001.pdf
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