Vaccine Info

VAX-24 Pneumococcal Conjugate Vaccine

Authored by
Last reviewed
July 12, 2023
Fact checked by
Robert Carlson, MD

VAX-24 Pneumococcal Conjugate Vaccine

Vaxcyte Inc.'s VAX-24 is an investigational 24-valent PCV candidate designed to prevent IPD, which can be most serious for infants, young children, older adults, and those with immune deficiencies or certain chronic health conditions. The public health community affirms the need for vaccines that offer broader protection to prevent IPD. VAX-24 is intended to improve the standard-of-care PCVs for children and adults by covering the serotypes responsible for most of the pneumococcal disease currently in circulation. Vaxcyte aims to efficiently create and deliver high-fidelity, broad-spectrum vaccines, such as VAX-24, by using modern synthetic techniques, including advanced chemistry and the XpressCF™ cell-free protein synthesis platform. Vaxcyte is deploying this approach with VAX-24 to add more pneumococcal strains without compromising the overall immune response.

Vaxcyte is re-engineering the way highly complex vaccines are made through modern synthetic techniques, including advanced chemistry and the XpressCF™ cell-free protein synthesis platform, exclusively licensed from Sutro Biopharma, Inc. Unlike conventional cell-based approaches, the Company's system for producing difficult-to-make proteins and antigens is intended to accelerate its ability to efficient create and deliver high-fidelity vaccines with enhanced immunological benefits efficientlyccal disease (PD) is an infection caused by Streptococcus pneumoniae (pneumococcus) bacteria. It can result in IPD, including meningitis and bacteremia, and non-invasive PD, including pneumonia, otitis media, and sinusitis. In the United States, approximately 320,000 people get pneumococcal pneumonia yearly, which is estimated to result in about 150,000 hospitalizations and 5,000 deaths. Pneumococci also cause over 50% of all cases of bacterial meningitis in the United States. Antibiotics are used to treat PD, but some strains of the bacteria have developed resistance to treatments. The morbidity and mortality due to PD are significant, particularly for young children and older adults, underscoring the need for a more broad-spectrum vaccine.

The FDA awarded Breakthrough Therapy Designation on January 5, 2023, and cleared the Company's infant Investigational New Drug application for VAX-24 on February 21, 2023. The first participants were dosed in the Phase 2 study of VAX-24 in healthy infants on March 30, 2023. On April 17, 2023, the Company announced positive clinical trial results.

Vaxcyte (Nasdaq: PCVX) is a vaccine innovation company engineering high-fidelity vaccines to protect humankind from the consequences of bacterial diseases. 


July 11, 2023 - Vaxcyte, Inc. announced that the ongoing Phase 2 study of VAX-24 in healthy infants is advancing to the second and final stage of the study. 

Clinical Trials

No clinical trials found