Safety, Tolerability, and Immunogenicity of VAX-31 in Adults ≥50 Years With Immunobridging to Adults 18-49
← catalyst calendarNCT07284654 · readout ≤ 165 d
Sponsored by Vaxcyte, Inc. (industry) · PCVX — their whole pipeline →.
Phase
Phase 3
Status
Active, not recruiting
Study type
Interventional
Design
Randomized · Quadruple · Prevention
Enrollment
4,049actual
Sites
30
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 | 2025-12-01 | actual | When the study began enrolling |
| Primary completion | Jan 2027 | estimated | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | Jan 2027 | estimated | The whole study's end, after follow-up |
| First posted | 2025-12-16 | actual | When this record first appeared on the registry |
| Results posted | — | When the sponsor posted results to the registry | |
| Record updated | 2026-05-15 | actual | The sponsor's own last edit to this record — every projection above is as current as this date |
What it studies
Condition
- Pneumococcal Vaccines
Interventions
- Biological: 31 valent pneumococcal conjugate vaccine
- Biological: PCV20 — also filed as Prevnar 20
- Biological: PCV21 — also filed as Capvaxive
Primary outcomes
what the primary-completion date above is the date OFSerotype-specific OPA geometric mean titers (GMT) in 50 year olds and above
measured 1 month after vaccination
Percentage of subjects reporting solicited local adverse events (AE) (redness, swelling, and pain at injection site)
measured up to 7 days after vaccination
Percentage of subjects reporting solicited systemic AE (fever, headache, fatigue, muscle pain, and joint pain)
measured up to 7 days after vaccination
Percentage of subjects reporting unsolicited AE
measured up to 31 days after vaccination
Percentage of subjects reporting serious adverse events (SAE), new onset of chronic illness (NOCI), and medically attended adverse events (MAAE)
measured up to 6 Months after vaccination
Serotype-specific OPA geometric mean titers (GMT) in 18 to 49 year olds and 50 to 64 year olds
measured 1 month after vaccination
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