NCT07284654

Safety, Tolerability, and Immunogenicity of VAX-31 in Adults ≥50 Years With Immunobridging to Adults 18-49

A Phase 3, Randomized, Double-Blind, Active-Controlled Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of VAX-31 in Healthy Subjects 50 Years of Age and Older With Immunobridging to Subjects 18-49 Years of Age

• Status: Active Not Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 4,049 (actual)
• Sponsor: Vaxcyte, Inc. · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

The primary objectives of this study are to evaluate the safety, tolerability, immunologic noninferiority (for shared serotypes) and immunologic superiority (for novel serotypes) of VAX-31 compared to PCV21 and PCV20 in adults ≥50 years of age, and to bridge the immune responses induced by VAX-31 in adults 50-64 years of age to adults 18-49 years of age.

Conditions

• Pneumococcal Vaccines

Interventions

Type	Name	Description
BIOLOGICAL	31 valent pneumococcal conjugate vaccine	0.5 mL of VAX-31 will be administered into the deltoid muscle
BIOLOGICAL	PCV20	0.5 mL of the 20 valent pneumococcal conjugate vaccine will be administered into the deltoid muscle
BIOLOGICAL	PCV21	0.5 mL of the 21 valent pneumococcal conjugate vaccine will be administered into the deltoid muscle

Timeline

• Start date: 2025-12-01
• Primary completion: 2027-01-01
• Completion: 2027-01-01
• First posted: 2025-12-16
• Last updated: 2026-03-31

Locations

30 sites across 1 country: United States

Regulatory

• FDA-regulated drug study