Pfizer’s Phase 3 BEATRIX trial – now open and recruiting – marks a significant milestone in the effort to develop a licensed maternal vaccine against group B Strep. The study is evaluating GBS6, a six‑valent conjugate vaccine given during pregnancy to help protect babies from GBS infection. [clinicaltrials.gov]
The trial involves healthy pregnant women and people aged 49 or younger who are 24–36 weeks’ pregnant. Each participant receives one injection (vaccine or placebo) and takes part for up to 14 months. Babies are followed for around a year, with some continuing to 19 months.
BEATRIX is being carried out across a wide network of international research sites, reflecting the global urgency of preventing GBS disease. ClinicalTrials.gov lists a large number of locations in North America, Europe, and Asia.
The study began in August 2025, with results expected after the primary completion date in November 2028 and final completion in March 2029.
GBS remains a leading cause of severe infection in newborns, and current prevention methods cannot eliminate all risk. A maternal vaccine could offer a major breakthrough. GBSS will continue to follow this important research and share updates as they become available.
Frequently Asked Questions (FAQ)
What is the BEATRIX trial?
BEATRIX is a Phase 3 clinical trial testing Pfizer’s new GBS6 maternal vaccine to see whether it is safe and effective at helping to protect newborns from group B Strep infection. https://clinicaltrials.gov/study/NCT07160244#study-overview
How does the vaccine work?
GBS6 is given during pregnancy. It aims to stimulate protective antibodies in the mother, which can then be passed to the baby before birth.
Who can join the study?
Healthy pregnant women and people aged 49 or younger, who are 24–36 weeks pregnant with a single baby, and who meet screening requirements including a normal fetal ultrasound and negative tests for HIV, syphilis, and hepatitis B. https://clinicaltrials.gov/study/NCT07160244#participation-criteria
What does taking part involve?
Participants receive one injection (the vaccine or placebo) and will have 3–4 study visits, some by phone. Follow‑up continues for up to 14 months for the pregnant participant and up to 12–19 months for the baby.
Where is the trial happening?
It’s running across many countries worldwide, with sites in North America, Europe, and Asia. ClinicalTrials.gov lists all locations. https://clinicaltrials.gov/study/NCT07160244#contacts-and-locations
Why is a GBS vaccine needed?
GBS can cause life‑threatening infections in newborns. Current prevention methods don’t stop all cases. A safe, effective maternal vaccine could reduce the burden of illness around the world.
For more information
There’s more information on the Clinical Trials website here and on Pfizer’s website here.
GBSS will continue to follow this important research and share updates as they become available. Sign up to receive updates here.
