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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

Status
Recruiting
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07160244
Enrollment
6000
Registered
2025-09-08
Start date
2025-08-25
Completion date
2029-03-02
Last updated
2026-02-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy

Keywords

group B streptococcus, maternal immunization, vaccine

Brief 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.

Interventions

Multivalent Group B streptococcus vaccine

BIOLOGICALPlacebo

Saline Control

BIOLOGICALInfanrix hexa

Vaccine administered in a subset of infant participants as per the national immunization schedule

BIOLOGICALPrevenar 20

Vaccine administered in a subset of infant participants as per the national immunization schedule

BIOLOGICALPediarix

Vaccine administered in a subset of infant participants as per the national immunization schedule

BIOLOGICALPrevnar 20

Vaccine administered in a subset of infant participants as per the national immunization schedule

BIOLOGICALInfanrix

Vaccine administered in a subset of infant participants as per the national immunization schedule

Sponsors

Pfizer
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
1 Days to 49 Years
Healthy volunteers
Yes

Inclusion criteria

Key Inclusion criteria- Maternal: * 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. Key

Exclusion criteria

- Maternal: * 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). Key Inclusion criteria- Infant Participants \- Evidence of a signed and dated ICD signed by the parent(s)/legally authorized representative or legal guardian Key

Design outcomes

Primary

MeasureTime frame
The proportion of maternal participants reporting prespecified local reactions within 7 days following study interventionWithin 7 days
The proportion of maternal participants reporting prespecified systemic events within 7 days following study interventionWithin 7 days
The proportion of maternal participants reporting adverse events (AEs) through 1 month following study intervention1 month
The proportion of maternal participants reporting serious adverse events (SAEs) through 6 months after delivery6 months after delivery
The proportion of maternal participants reporting medically attended adverse events (MAAEs) through 6 months after delivery6 months after delivery
The proportion of infant participants born to pregnant women who were vaccinated with GBS6 during pregnancy reporting adverse events (AEs) from birth through 1 month of ageBirth to 1 month of age
The proportion of infant participants born to pregnant women who were vaccinated with GBS6 during pregnancy reporting serious adverse events (SAEs) from birth through end of the studyThrough study completion, at least 1 year
The proportion of infant participants born to pregnant women who were vaccinated with GBS6 during pregnancy reporting medically attended events (MAAEs) from birth through 6 months of ageBirth to 6 months of age
To measure the relative risk reduction in the proportion of infant participants at birth with GBS serotype-specific IgG antibody concentrations below predefined serotype-specific GBS late onset disease thresholds in the GBS6 group to the placebo groupBirth
To measure the relative risk reduction in the proportion of infant participants at birth with GBS serotype-specific IgG antibody concentrations below predefined serotype-specific GBS early onset disease thresholds in the GBS6 group to the placebo groupBirth
To evaluate the aggregate predicted VE combining all 6 serotypes in GBS6 to provide protection from invasive GBS late onset disease based on serotype specific anti-CPS IgG concentrations measured in infants at birth.Birth
To evaluate the aggregate predicted VE combining all 6 serotypes in GBS6 to provide protection from invasive GBS early onset disease based on serotype specific anti-CPS IgG concentrations measured in infants at birth.Birth

Secondary

MeasureTime frame
To measure GBS serotype-specific opsonophagocytic titers in infant participants at birth by geometric mean ratio between GBS6 group versus placebo group and by the difference in seroresponse rates between GBS6 group and placebo groupBirth
To describe anti-CPS IgG antibody levels predicted to provide protection from invasive GBS disease (all disease) caused by the 6 individual vaccine serotypes in infants when GBS6 is administered to healthy pregnant women.Birth
To describe anti-CPS IgG antibody levels in infant participants born to maternal participants vaccinated with GBS6.Birth
To describe anti-CPS IgG antibody levels predicted to provide protection from invasive GBS LOD and EOD, separately, caused by the 6 individual vaccine serotypes (Ia, Ib, II, III, IV, and V) in infants when GBS6 is administered to healthy pregnant women.Birth
To measure GBS serotype-specific IgG by geometric mean concentration in maternal participants at 1 month after vaccination and at delivery.1 month after vaccination and at delivery
Compare the proportion of infants with anti-diphtheria toxoid and pneumococcal IgG responses at 1 month post-primary and toddler doses between GBS6 and placebo groups, including predefined IgG levels and geometric mean ratios.1 month after the primary vaccination series and 1 month after the toddler dose

Countries

Argentina, Finland, Japan, South Korea, Spain, Taiwan, United Kingdom, United States

Contacts

CONTACTPfizer CT.gov Call Center
ClinicalTrials.gov_Inquiries@pfizer.com1-800-718-1021
STUDY_DIRECTORPfizer CT.gov Call Center

Pfizer

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026