A Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of VAX-31 With Influenza Vaccine in Adults ≥ 50 Years of Age
← catalyst calendarNCT07365826 · readout ≤ 224 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
1,390actual
Sites
25
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 | 2026-01-12 | actual | When the study began enrolling |
| Primary completion | Mar 2027 | estimated | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | Mar 2027 | estimated | The whole study's end, after follow-up |
| First posted | 2026-01-26 | actual | When this record first appeared on the registry |
| Results posted | — | When the sponsor posted results to the registry | |
| Record updated | 2026-06-30 | 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: Seasonal Influenza Vaccine (SIV) (Flublok)
- Biological: Placebo
Primary outcomes
what the primary-completion date above is the date OFFor each of the 32 serotypes (the 31 serotypes included in VAX-31, and serotype 20B), the ratio (co-administration group to sequential administration group) of opsonophagocytic activity (OPA) geometric mean titers (GMT) in evaluable participants
measured 1 Month after VAX-31 vaccination
For each of the strains in SIV, the ratio (co-administration group to sequential administration group) of hemagglutination inhibition (HAI) GMT in evaluable participants
measured 1 Month after SIV administration
Percentage of participants reporting solicited local adverse events (AE) within 7 days after Day 1 and Month 1 vaccination (redness, swelling, and pain at injection site) in each group
measured 7 days after each vaccination
Percentage of participants reporting solicited systemic AE within 7 days after Day 1 and Month 1 vaccination (fever, headache, fatigue, muscle pain, and joint pain) in each group
measured 7 days after each vaccination
Percentage of participants reporting unsolicited AE within 1 month after Day 1 and Month 1 vaccination in each group
measured 7 days after each vaccination
Percentage of participants reporting NOCI, MAAE, and SAE within 6 months after last vaccination in each group
measured 6 Months after last vaccination
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