31-Valent Pneumococcal Conjugate Vaccine Candidate Doses First Person

Vaxcyte, Inc. today announced that the first participants were dosed in a Phase 1/2 clinical study for VAX-31, a 31-valent pneumococcal conjugate vaccine (PCV) candidate designed to prevent invasive pneumococcal disease (IPD) in adults.

Vaxcyte stated it expects to announce topline data from the Phase 1/2 study in the second half of 2024.

"We are pleased to initiate the first adult clinical study of VAX-31, which is the broadest-spectrum PCV to enter the clinic, with the potential to protect against approximately 95 percent of IPD circulating in the U.S. adult population," said Grant Pickering, Chief Executive Officer and Co-founder of Vaxcyte, in a press release on November 9, 2023.

"Leveraging the foundation established by our lead PCV candidate, VAX-24, we believe we have an opportunity to deliver a best-in-class PCV franchise that provides the broadest spectrum of coverage and improved immune responses compared to the standard-of-care in adults today."

The VAX-31 Phase 1/2 clinical study is a randomized, observer-blind, active-controlled, dose-finding clinical study designed to evaluate the safety, tolerability, and immunogenicity of VAX-31 compared to Prevnar 20® in healthy adults aged 50 and older.

Pneumococcal disease (PD) is an infection caused by Streptococcus pneumoniae bacteria. It can result in IPD, including meningitis and bacteremia, and non-invasive PD, including pneumonia, otitis media, and sinusitis. 

The U.S. National Center for Health Statistics Mortality Surveillance reported on October 27, 2023, that most respiratory disease deaths were recently related to pneumonia, not COVID-19 or influenza. Precision Vax posts additional PCV vaccine and candidate news. 

The U.S. CDC's pneumococcal vaccine schedules were updated in 2023.