BEATRIX: A Study to Learn About a Group B Streptococcus Vaccine in Healthy Pregnant Women and Their Babies
A Phase 3, Randomized, Placebo-Controlled, Double-Blinded Trial to Evaluate the Safety, Tolerability, and Immunogenicity of a Multivalent Group B Streptococcus Vaccine in Healthy Pregnant Women and Their Infants
Pfizer
6,000 participants
Aug 25, 2025
INTERVENTIONAL
Conditions
Summary
BEATRIX (group B strEptococcus mATeRnal and Infant VaX study) The purpose of this study is to learn about the safety and how the group B streptococcus (GBS) vaccine works in pregnant women and their babies. This study is seeking healthy pregnant participants: * aged 49 or younger who can join. * between 24 and 36 weeks of gestation ("Gestational age" is a medical term used to describe how far along your pregnancy is) * had a fetal ultrasound examination performed with no major fetal abnormalities observed * documented negative for HIV, syphilis and Hepatitis B All participants in this study will receive only 1 shot in an arm. This could either be a group B streptococcus 6-valent polysaccharide conjugate vaccine (GBS6) or placebo. Placebo is an inactive substance used in the study for comparison purposes; in this study, the placebo injection will be saline (saltwater). The pregnant participants may take part in this study for a maximum of 14 months (6 months after delivery) , and their babies for about 12 months after they are born. The pregnant participants will need to visit the research site at least 3 to 4 times with some visits permitted to occur over the telephone. A subset of infants will be asked to take part in the study for up to 19 months. The subset will receive diphtheria toxoid-containing vaccine and/or pneumococcal vaccine following each country's standard immunization plan and have blood drawn 1 month after completion of the primary and/or toddler (booster) doses.
Eligibility
Inclusion Criteria6
- Healthy pregnant women ≤49 years of age who are between 24 0/7 and 36 0/7 weeks of gestation on the day of planned vaccination, with an uncomplicated, singleton pregnancy, and who have no known increased risk of complications.
- Had a fetal anomaly ultrasound examination with no significant fetal abnormalities observed.
- Documented negative human immunodeficiency virus (HIV) antibody test, syphilis test, and hepatitis B virus (HBV) surface antigen test during this pregnancy and prior to randomization.
- Capable of giving personal signed informed consent.
- Willing to give informed consent for her infant to participate in the study.
- \- Evidence of a signed and dated ICD signed by the parent(s)/legally authorized representative or legal guardian
Exclusion Criteria8
- Prepregnancy body mass index (BMI) of >40 kg/m2.
- Current pregnancy complications or abnormalities that may increase the risk associated with the participation in and completion of the study.
- Prior pregnancy complications or abnormalities that, based on the investigator's judgment, may increase the risk associated with the participation in and completion of the study.
- History of microbiologically proven invasive disease caused by GBS in the current pregnancy.
- A known or suspected infection during the current pregnancy that may increase the risk of complications in pregnancy (eg, active tuberculosis, syphilis, primary genital herpes simplex, malaria).
- \- Children or grandchildren who are direct descendants of investigator site staff or sponsor and sponsor delegate employees directly involved in the conduct of the study.
- \- Children with a known or suspected contraindication to any vaccine administered in the infant vaccine immunogenicity subset.
- Refer to the study contact for further eligibility details
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Interventions
Multivalent Group B streptococcus vaccine
Saline Control
Vaccine administered in a subset of infant participants as per the national immunization schedule
Vaccine administered in a subset of infant participants as per the national immunization schedule
Vaccine administered in a subset of infant participants as per the national immunization schedule
Vaccine administered in a subset of infant participants as per the national immunization schedule
Vaccine administered in a subset of infant participants as per the national immunization schedule
Locations(158)
View Full Details on ClinicalTrials.gov
For the most up-to-date information, visit the official listing.
NCT07160244