NCT07160244 · Pfizer
BEATRIX: A Study to Learn About a Group B Streptococcus Vaccine in Healthy Pregnant Women and Their Babies
What this study is about
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.
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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.
Interventions
BIOLOGICAL
Multivalent Group B streptococcus vaccine
Multivalent Group B streptococcus vaccine
BIOLOGICAL
Placebo
Saline Control
BIOLOGICAL
Infanrix hexa
Vaccine administered in a subset of infant participants as per the national immunization schedule
BIOLOGICAL
Prevenar 20
Vaccine administered in a subset of infant participants as per the national immunization schedule
BIOLOGICAL
Pediarix
Vaccine administered in a subset of infant participants as per the national immunization schedule
BIOLOGICAL
Prevnar 20
Vaccine administered in a subset of infant participants as per the national immunization schedule
BIOLOGICAL
Infanrix
Vaccine administered in a subset of infant participants as per the national immunization schedule
Primary outcome measures
The proportion of maternal participants reporting prespecified local reactions within 7 days following study intervention
Time frame: Within 7 days
The proportion of maternal participants reporting prespecified systemic events within 7 days following study intervention
Time frame: Within 7 days
The proportion of maternal participants reporting adverse events (AEs) through 1 month following study intervention
Time frame: 1 month
The proportion of maternal participants reporting serious adverse events (SAEs) through 6 months after delivery
Time frame: 6 months after delivery
The proportion of maternal participants reporting medically attended adverse events (MAAEs) through 6 months after delivery
Time frame: 6 months after delivery
The proportion of maternal participants reporting adverse events of special interest (AESIs) through 6 months after delivery.
Time frame: 6 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 age
Time frame: Birth 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 study
Time frame: Through 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 adverse events (MAAEs) from birth through 6 months of age
Time frame: Birth to 6 months of age
The proportion of infant participants born to pregnant women who were vaccinated with GBS6 during pregnancy reporting adverse events of special interest (AESIs) from birth through end of study
Time frame: Through study completion, at least 1 year
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 group
Time frame: Birth
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 group
Time frame: Birth
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.
Time frame: 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.
Time frame: Birth
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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 judgmen
Where
- Birmingham, Alabama
- Dothan, Alabama
- Mobile, Alabama
- Phoenix, Arizona
- Tucson, Arizona
- Lancaster, California
- Loma Linda, California
- Palo Alto, California
- Aurora, Colorado
- Margate, Florida
- North Miami Beach, Florida
- Panama City, Florida
And 49 more locations — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 9, 2026 · Source of record for eligibility and locations