A Study of mRNA-1345 Vaccine Targeting Respiratory Syncytial Virus in Pregnant Women and in Infants Born to Vaccinated Mothers
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Phase
Phase 2
Status
Completed
Study type
Interventional
Design
Randomized · Quadruple · Prevention
Enrollment
360actual
Sites
56
Countries
Canada, Chile, Denmark +5
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 | 2023-11-15 | actual | When the study began enrolling |
| Primary completion | 2026-05-25 | actual | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | 2026-05-25 | actual | The whole study's end, after follow-up |
| First posted | 2023-11-22 | actual | When this record first appeared on the registry |
| Results posted | — | When the sponsor posted results to the registry | |
| Record updated | 2026-06-10 | 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 OFNumber of Maternal Participants with Solicited Local and Systemic Adverse Reactions (ARs)
measured Up to Day 7 (7 days post vaccination)
Number of Maternal Participants with Unsolicited Adverse Events (AEs)
measured Up to Day 28 (28 days post vaccination)
Number of Maternal Participants with Medically-Attended AEs (MAAEs)
measured Day 1 to Month 6 (6 months postdelivery)
Number of Maternal Participants with Adverse Events of Special Interest (AESIs)
measured Day 1 to Month 12 (12 months postdelivery)
Number of Maternal Participants with Serious Adverse Events (SAEs)
measured Day 1 to Month 12 (12 months postdelivery)
Number of Maternal Participants with AEs Leading to Discontinuation
measured Day 1 to Month 12 (12 months postdelivery)
Number of Maternal Participants With Pregnancy Outcomes
measured Day 1 to Month 12 (12 months postdelivery)
Number of Infant Participants with MAAEs
measured Day 1 (birth) to Month 12
Number of Infant Participants with AESIs
measured Day 1 (birth) to Month 12
Number of Infant Participants with SAEs
measured Day 1 (birth) to Month 12
Number of Infant Participants With Birth Outcomes
measured Day 1 (birth) to Month 12
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