Safety, Tolerability, and Immunogenicity Study of a 31-Valent Pneumococcal Conjugate Vaccine (VAX-31) in Adults

Phase 1/2 Completed 1015 enrolled Vaxcyte, Inc.

RandomizedParallel-groupQuadruple-blindPrevention

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.

Timeline

Start: 2023-11-08
Primary completion: 2024-07-17
Completion: 2024-07-17

Publications

Wassil J, Fairman J, Fierro CA, Clark J, Bennett S, Johnson D, Jiang Q, Migone TS, Paschenko A, Simon JK, Lamola S, Sisti M. Safety, tolerability, and immunogenicity of a 31-valent pneumococcal conjugate vaccine (VAX-31) in healthy adults aged 50 years and older from the USA: a phase 1/2, double-blinded, active-controlled, parallel-group, dose-finding randomised clinical trial. Lancet Infect Dis. 2026 Mar 18:S1473-3099(26)00059-9. doi: 10.1016/S1473-3099(26)00059-9. Online ahead of print.

Drugs

Evaluation	Drug	Modality	Dose	Route
Comparator	PCV20	Vaccine	0.5 ml	Intramuscular
Subject	VAX-31	Vaccine	1.1 ug	Intramuscular
Subject	VAX-31	Vaccine	1.65 ug	Intramuscular
Subject	VAX-31	Vaccine	2.2 ug	Intramuscular
Subject	VAX-31	Vaccine	3.3 ug	Intramuscular
Subject	VAX-31	Vaccine	4.4 ug	Intramuscular

Indications

No indication recorded.