What is the GBS6 vaccine studying for healthy pregnant women and their babies?

The GBS6 vaccine is being studied to learn about its safety and how it works in pregnant women and their infants. Researchers want to understand the immune response and any possible side effects. This study is sponsored by Pfizer and aims to improve protection against group B streptococcus infection in newborns.

Is there any cost to participate in this healthy pregnancy clinical trial?

Study-related care, including the vaccine or placebo and all trial visits, is provided at no cost. Personal travel expenses may vary and are not guaranteed to be covered. Participants should plan for their own transportation and related costs.

Actively Recruiting

Phase 3

Age: 1Day - 49Years

All Genders

Healthy Volunteers

ID07160244

A Phase 3 Randomized, Placebo-Controlled, Double-Blinded Trial Evaluating Safety and Immune Response of a Multivalent Group B Streptococcus Vaccine in Healthy Pregnant Women and Their Infants

Q: Who may be eligible for this healthy pregnancy clinical trial?

Healthy pregnant women aged 18 to 49 with a single pregnancy between 24 and 36 weeks of gestation may be eligible. Participants must have no major fetal abnormalities and negative tests for HIV, syphilis, and hepatitis B. Both mother and infant must be willing to participate. Please review eligibility criteria for more details.

Led by Pfizer · Updated on 2026-05-29

6000

Participants Needed

179

Research Sites

16 weeks

Total Duration

AI-Summary

What this Trial Is About

Researchers are evaluating the safety and immune response of a group B streptococcus (GBS) vaccine in healthy pregnant women and their babies. The study is a phase 3, randomized, placebo-controlled, double-blinded trial aiming to understand how the vaccine works in pregnancy and the infant's early life. The focus is on pregnant participants aged 49 or younger between 24 and 36 weeks of gestation with no major fetal abnormalities and negative tests for HIV, syphilis, and hepatitis B. Participants will receive a single injection of either the GBS6 vaccine or a saline placebo. The study also involves vaccines for infants, including combinations protecting against diphtheria, tetanus, pertussis, hepatitis B, polio, Haemophilus influenzae type b, and pneumococcal strains, given according to each country's immunization schedule. Pregnant participants are followed for up to 14 months, including 6 months after delivery. A subset of infants will have additional follow-up for up to 19 months receiving standard vaccines with blood samples taken after primary and booster doses. Participants will attend 3 to 4 visits, some by telephone, for safety and immune response assessments. Researchers will monitor local and systemic reactions, adverse events, and serious adverse events in mothers and infants for up to one year after birth. Key measures include antibody levels against GBS serotypes and vaccine effectiveness predictions based on infant antibody concentrations. Infant immunity to other vaccines is also compared between groups. This careful monitoring provides safety and immune response data throughout the study duration.

CONDITIONS

Brief Title

BEATRIX: A Study to Learn About a Group B Streptococcus Vaccine in Healthy Pregnant Women and Their Babies

Who Can Participate

Age: 1Day - 49Years

All Genders

Healthy Volunteers

Eligibility Criteria

You may qualify if you...

Healthy pregnant women aged 49 years or younger
Pregnancy between 24 0/7 and 36 0/7 weeks of gestation
Singleton pregnancy with no known increased risk of complications
Fetal ultrasound showing no significant fetal abnormalities
Documented negative tests for HIV, syphilis, and hepatitis B during pregnancy
Ability to give signed informed consent
Willingness to give informed consent for infant participation
Infant participants must have signed and dated informed consent from parent or legal guardian

You will not qualify if you...

Prepregnancy body mass index (BMI) greater than 40 kg/m2
Current pregnancy complications or abnormalities increasing risk for study participation
Prior pregnancy complications judged to increase risk
History of invasive group B streptococcus disease in current pregnancy
Known or suspected infections during pregnancy that increase risk (e.g., active tuberculosis, syphilis, primary genital herpes simplex, malaria)
Infant descendants of study staff or sponsor employees involved in the study
Infants with known or suspected contraindications to vaccines used in the infant immunogenicity subset

AI-Screening

AI-Powered Screening

Complete this quick 3-step screening to check your eligibility

Your Study Journey

Screening

Duration - 2 to 4 weeks

Participants are screened for eligibility to participate in the trial.

1 visit (in-person)

Treatment

Duration - From 24 0/7 to 36 0/7 weeks of gestation

Participants receive either the multivalent Group B streptococcus vaccine or placebo during pregnancy.

1 vaccination visit during pregnancy

Post-treatment Monitoring

Duration - Up to 6 months after delivery for mothers; up to at least 1 year for infants

Participants and their infants are monitored for adverse events and immune responses after vaccination.

Multiple follow-up visits up to 6 months after delivery for mothers; infant assessments from birth through at least 1 year

Trial Site Locations

Total: 179 locations

Center for Research in Women's Health

Birmingham, Alabama, United States, 35233

Actively Recruiting

Children's of Alabama

Birmingham, Alabama, United States, 35233

Actively Recruiting

University of Alabama at Birmingham - School of Medicine

Birmingham, Alabama, United States, 35233

Actively Recruiting

University of Alabama at Birmingham Women & Infants Center

Birmingham, Alabama, United States, 35294

Actively Recruiting

SEC Clinical Research

Dothan, Alabama, United States, 36305

Actively Recruiting

ClinMed

Phoenix, Arizona, United States, 85004

Actively Recruiting

Valleywise Comprehensive Health Center Women's Clinic

Phoenix, Arizona, United States, 85008

Actively Recruiting

Valleywise Health Medical Center

Phoenix, Arizona, United States, 85008

Actively Recruiting

Genesis OB/GYN

Tucson, Arizona, United States, 85741

Actively Recruiting

Eclipse Clinical Research

Tucson, Arizona, United States, 85745

Actively Recruiting

Antelope Valley Medical Center

Lancaster, California, United States, 93534

Actively Recruiting

Chemidox Clinical Trials

Lancaster, California, United States, 93534

Actively Recruiting

Lucile Packard Children's Hospital

Palo Alto, California, United States, 94304

Not Yet Recruiting

Stanford Obstetrics Clinic

Palo Alto, California, United States, 94304

Not Yet Recruiting

Stanford University Medical Center

Palo Alto, California, United States, 94304

Not Yet Recruiting

Stanford University

Palo Alto, California, United States, 94304

Not Yet Recruiting

Anschutz Health Sciences Building