London recruitment opens
Pregnant women in London are being invited to consider joining a phase-three study of a vaccine candidate against group B streptococcus, a bacterial infection that can be severe in newborn babies. The BEATRIX study is recruiting through 10 hospitals across the UK, including the Royal Free Hospital in Hampstead, St George’s Hospital in Tooting and St Mary’s Hospital in Paddington. The announcement is an invitation to a research study, not the introduction of a routine maternity vaccination.
What the study is testing
BEATRIX is a randomised, placebo-controlled, double-blinded trial of GBS6, a multivalent vaccine candidate designed to prompt maternal antibodies that may pass to a baby through the placenta. It is sponsored by Pfizer and remains investigational; there is currently no licensed vaccine for this purpose. Participants receive one injection in the arm between 24 and 36 weeks of pregnancy. That injection may contain GBS6 or saline placebo, with allocation decided at random.
The study is intended to examine safety, tolerability and immune responses in pregnant participants and their infants. Its registered measures include local and systemic reactions after injection, adverse events during follow-up and antibody concentrations at birth. Those measures are important to assessing a candidate vaccine, but the recruitment announcement does not establish that it prevents infection or guarantees protection for an individual baby.
Why the infection is a focus
Group B streptococcus is described as the most common cause of life-threatening infection in newborn babies. It can lead to sepsis, pneumonia and meningitis. In the UK and Ireland, around one in every 1,000 babies develops a GBS infection during the first three months of life. The study information estimates that about 50 babies die each year and that roughly 70 survivors have long-term disabilities, which may include hearing or vision problems, cerebral palsy or developmental difficulties.
The burden is not evenly distributed. Serious infection rates are estimated to be 51% higher among Black babies and 28% higher among Asian babies than among white babies. Recruitment therefore particularly encourages eligible Black and Asian women to be represented. Those population-level figures do not predict an individual pregnancy outcome; eligibility and participation are assessed by the study team.
What participation involves
Healthy pregnant women aged 49 or younger may be considered if they are between 24 and 36 weeks pregnant and meet screening requirements. The registry specifies an uncomplicated singleton pregnancy, a fetal ultrasound with no significant abnormality identified, and documented negative tests for HIV, syphilis and hepatitis B during the pregnancy, among other criteria. These are key entry conditions rather than a substitute for an individual clinical assessment.
Participants may remain in the study for up to 14 months, ending about six months after giving birth. Babies are generally followed for around 12 months; a subset may take part for up to 19 months while researchers examine immune responses after routine childhood immunisations. The adult participant is expected to make at least three or four research-site visits, although some follow-up may be by telephone.
A London role in a wider trial
The trial began internationally in August 2025 and is still recruiting. The new London appeal makes local access more visible while linking three maternity hospitals to a much wider programme. Anyone interested should discuss the opportunity with the relevant research team, who can explain the full criteria, possible risks, follow-up and voluntary consent process. Results are not expected before the primary study completion date currently estimated for late 2028.
