Vaxcyte Announces Publication of Positive Phase 1/2 Data for VAX-31 Vaccine in The Lancet

Key Facts

1The Lancet Infectious Diseases published positive Phase 1/2 data for VAX-31, a 31-valent pneumococcal conjugate vaccine candidate.

2Vaxcyte is advancing the high-dose VAX-31 into a comprehensive Phase 3 adult program.

3Topline data from the OPUS-1 pivotal noninferiority trial is expected in the fourth quarter of 2026.

Vaxcyte (PCVX) announced that the prestigious medical journal The Lancet Infectious Diseases has published positive results from its Phase 1/2 study of VAX-31. VAX-31 is a 31-valent pneumococcal conjugate vaccine candidate designed to provide broader protection against bacterial infections. Following these successful results, the company plans to advance the high-dose version of the vaccine into a comprehensive Phase 3 clinical program for adults. This peer-reviewed publication validates the vaccine's immunogenicity and safety profile, positioning it as a potential best-in-class competitor in the market. Investors are now looking toward the OPUS-1 pivotal trial, with topline data anticipated in the fourth quarter of 2026. The news reinforces Vaxcyte's clinical pipeline and reduces long-term development risks for its lead candidate.