Clinical Trials

This phase of the study enrolled 360 healthy pregnant volunteers. GBS6 triggered robust maternal antibody responses against all six GBS CPS serotypes included in the vaccine. The antibodies were efficiently transferred to the infants at ratios of between 0.4-1.3 depending on GBS6 group.

Results from the study were published in The New England Journal of Medicine (NEJM), and will inform the company’s planned phase 3 clinical development programme.

The safety profile of the vaccine was similar between the vaccine and placebo groups, with local reactions generally remaining mild or moderate and of short duration.

Annaliesa Anderson PhD, senior vice president and chief scientific officer of vaccine research and development at Pfizer, commented: “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. The findings published in NEJM provide hope that maternal vaccination with GBS6 may protect infants against GBS, potentially helping to prevent thousands of cases of illness annually, if it is successfully developed and approved. Building on decades of expertise and knowledge in vaccines, we are committed to helping protect newborns and young infants through maternal immunisation.”