NCT07365826Phase 3Active not recruiting

A Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of VAX-31 With Influenza Vaccine in Adults ≥ 50 Years of Age

Compare the available registry edits below. Primary completion is the date data collection ends for the main study measures; it does not tell you when results will be published.

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Primary completion2027-03Estimated

Enrollment · participants1390Actual

Source updated2026-06-30Last update listed in the registry record

Version history

Changes to this trial

Last 12 months

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Posted 2026-03-31 · 3 fields changed

Participant count type changed

− Before

~~Estimated~~

+ After

Actual

Enrollment · participant count changed

− Before

~~1300 participants (planned)~~

+ After

1390 participants (actual)

Recruitment status changed

− Before

~~Recruiting~~

+ After

Active not recruiting

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Study details

Conditions studied

Pneumococcal Vaccines

Treatments or interventions studied

31-valent pneumococcal conjugate vaccineBiological
Seasonal Influenza Vaccine (SIV) (Flublok)Biological
PlaceboBiological

Primary outcomes · main study measures

Read the study measures

measure: For 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; timeFrame: 1 Month after VAX-31 vaccination; measure: For each of the strains in SIV, the ratio (co-administration group to sequential administration group) of hemagglutination inhibition (HAI) GMT in evaluable participants; timeFrame: 1 Month after SIV administration; measure: 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; timeFrame: 7 days after each vaccination; measure: 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; timeFrame: 7 days after each vaccination; measure: Percentage of participants reporting unsolicited AE within 1 month after Day 1 and Month 1 vaccination in each group; timeFrame: 7 days after each vaccination; measure: Percentage of participants reporting NOCI, MAAE, and SAE within 6 months after last vaccination in each group; timeFrame: 6 Months after last vaccination

History coverage

Research sample: selected versions from May 2023 onward plus a preceding baseline where available. Only selected fields were retained; endpoint measures were truncated to 300 characters. This is not complete trial or sponsor history. Daily snapshots begin when collection starts.

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