Maternal Vaccination May Protect Infants Against Invasive Group B Streptococcus Disease

Pfizer Inc. today announced data from a Phase 2 clinical study investigating its hexavalent capsular polysaccharide (CPS) conjugate Group B Streptococcus (GBS) vaccine candidate, GBS6.

This vaccine candidate is being developed for maternal administration to protect infants against invasive GBS disease.

In stage two of the three-part study, GBS6 generated robust maternal antibody responses against the six GBS CPS serotypes included in the vaccine, and these antibodies were efficiently transferred to infants at ratios of ~0.4-1.3 depending on the GBS6 group.

Based on a parallel natural history study conducted in South Africa, the Phase 2 study immunogenicity data suggest that GBS6 may offer meaningful protection against invasive GBS disease in newborns and young infants.

The results were published in an Original Article in The New England Journal of Medicine on July 20, 2023, and will inform a planned Phase 3 clinical development program.

“Group B Streptococcus can cause potentially devastating diseases in infants, including sepsis, pneumonia, and meningitis. Annually, there are nearly 400,000 cases of infant disease and approximately 138,000 stillbirths and infant deaths worldwide due to GBS,” said Annaliesa Anderson, Ph.D., Senior Vice President and Chief Scientific Officer, Vaccine Research and Development, Pfizer, in a press release on July 19, 2023.

“Building on decades of expertise and knowledge in vaccines, we are committed to helping protect newborns and young infants through maternal immunization.”

The U.S. CDC says bacteria called group B Streptococcus cause GBS disease.

GBS bacteria commonly live in people’s gastrointestinal and genital tracts. The genital tract is the part of the body involved in reproduction and includes the vagina in women.

Sometimes the bacteria invade the body and cause certain infections, which are known as GBS disease.