Vaxcyte Initiates Phase 2 Study Evaluating VAX-31 for the Prevention of Invasive Pneumococcal Disease in Infants

Core Insights - Vaxcyte has initiated a Phase 2 study for VAX-31, a 31-valent pneumococcal conjugate vaccine (PCV) aimed at preventing invasive pneumococcal disease (IPD) in infants, with topline data expected in mid-2026 and booster dose data approximately nine months later [1][2][3] - VAX-31 is designed to cover approximately 94% of IPD and 93% of acute otitis media in U.S. children under five, offering broader protection compared to current standard-of-care PCVs [2][7] - The study will compare VAX-31's safety, tolerability, and immunogenicity against Prevnar 20 (PCV20) in a randomized, double-blind format across two stages involving around 798 infants [3][4][5] Company Overview - Vaxcyte is focused on developing high-fidelity vaccines to combat bacterial diseases, with VAX-31 being the broadest-spectrum PCV candidate currently in clinical trials [9][10] - The company also has VAX-24, a 24-valent PCV candidate, which is in a Phase 2 study and aims to cover more serotypes than any existing infant PCV [9] - Vaxcyte employs modern synthetic techniques for vaccine development, including the XpressCF™ cell-free protein synthesis platform, to enhance the efficiency and immunological benefits of its vaccines [10] Industry Context - Pneumococcal disease, caused by Streptococcus pneumoniae, is a significant public health threat, particularly in children under five, leading to high rates of vaccine-preventable deaths globally [6] - The World Health Organization has identified Streptococcus pneumoniae as a top antibiotic-resistant pathogen, highlighting the urgent need for vaccines with broader coverage [6] - Current vaccines are insufficient to address the persistent threat of IPD, which includes severe conditions like meningitis and bacteremia, underscoring the importance of Vaxcyte's innovative vaccine candidates [2][6]