CI

At a glance

ClinicalIndex Comparison Record
Phase 2Completed· 1,015 enrolled
Drug / intervention
31 valent pneumococcal conjugate vaccine +1 morebiological
Likely dose
31 valent pneumococcal conjugate vaccine 0.5 mlfrom record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT06151288
NCT06151288Phase 2Completed

A Phase 1/2, Randomized, Observer-Blind, Dose-Finding, Active-Controlled, Parallel-Group, Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of a 31-Valent Pneumococcal Conjugate Vaccine (VAX-31) in Healthy Adults Aged 50 Years and Older

Vaxcyte, Inc.·interventional·Posted Nov 30, 2023·Updated Jul 28, 2025

In Brief

A Phase 2 clinical trial evaluating 31 valent pneumococcal conjugate vaccine and 20 valent pneumococcal conjugate vaccine for Pneumococcal Vaccines. Completed, enrolled 1,015 participants across 25 sites.

Detailed Summary

The objective of the study is to evaluate the safety, tolerability and immunogenicity of a single injection of VAX-31 at 3 dose levels compared to Prevnar 20™ (PCV20) in adults 50 to 64 years of age in Stage 1. Stage 2 will evaluate the safety, tolerability, and immunogenicity of a single injection of VAX-31 at 3 dose levels compared to PCV20 in adults aged 50 years and older.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
CountriesUnited States
Collaborators--

Timeline

Phase 2CompletedFinished
202420252026
First PostedNov 30, 2023
Enrollment StartNov 8, 2023
Primary CompletionJul 17, 2024
TodayJul 2, 2026
Enrollment to primary: 8 monthsPosted 2.6 years ago

Interventions

31 valent pneumococcal conjugate vaccinebiological

0.5 ml dose of VAX-31 was administered into the deltoid muscle at Day 1

20 valent pneumococcal conjugate vaccinebiological

0.5 ml dose of PCV20 was administered into the deltoid muscle at Day 1