A Phase 3 interventional study of Multivalent Group B streptococcus vaccine and Placebo in Healthy, sponsored by Pfizer. Recruiting at 219 sites in 15 countries. Open to participants aged 1 Day to 49 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-27.
Sponsored by Pfizer · Phase 3, Interventional, and Prevention
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:
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.
Pfizer is the lead sponsor of 3,334 studies on the registry; 149 are open to participants now.
Of its 601 completed or terminated interventional studies of FDA-regulated products, 391 (65%) have results posted.
Counted across the registry records on this site, refreshed daily.
Key Inclusion criteria- Maternal:
Key Exclusion criteria- Maternal:
Key Inclusion criteria- Infant Participants
- Evidence of a signed and dated ICD signed by the parent(s)/legally authorized representative or legal guardian
Key Exclusion Criteria - Infant Participants:
- 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.
Key Exclusion Criteria - Infant immunogenicity subset Participants:
- Children with a known or suspected to any vaccine administered in the infant vaccine immunogenicity subset.
Refer to the study contact for further eligibility details
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Multivalent group B streptococcus vaccine
Biological: Multivalent Group B streptococcus vaccine
Placebo
Biological: Placebo
Commercially available combination vaccine containing diphtheria, tetanus, pertussis (whooping cough), hepatitis B, poliomyelitis (polio), and Haemophilus influenzae type b (Hib)
Biological: Infanrix hexa
Commercially available vaccine that protects against 20 strains of Streptococcus pneumoniae
Biological: Prevenar 20
Commercially available combination vaccine containing diphtheria, tetanus, pertussis (whooping cough), hepatitis B, and polio
Biological: Pediarix
Commercially available vaccine that protects against 20 strains of Streptococcus pneumoniae
Biological: Prevnar 20
Commercially available combination vaccine containing diphtheria, tetanus, and pertussis
Biological: Infanrix
Multivalent Group B streptococcus vaccine
Also known as: GBS6
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
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
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 group
Time frame: Birth
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.
Time frame: Birth
To describe anti-CPS IgG antibody levels in infant participants born to maternal participants vaccinated with GBS6.
Time frame: 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.
Time frame: Birth
To measure GBS serotype-specific IgG by geometric mean concentration in maternal participants at 1 month after vaccination and at delivery.
Time frame: 1 month after vaccination and at delivery
Compare the proportion of infants with anti-diphtheria toxoid and/or pneumococcal IgG responses at 1 month post-primary and toddler doses between GBS6 and placebo groups, including predefined IgG levels and geometric mean ratios.
Time frame: 1 month after the primary vaccination series and 1 month after the toddler dose
Not enrolling at this site — choose another above.
Showing the first 100 of 219 sites across 15 countries. Choose a country and city above to see the rest.
Plan to share: Yes — Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.
Data sharing details ↗ · www.pfizer.com
Started Aug 2025 (actual). Primary completion is estimated for Nov 2028, 38 months after the start.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
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Studies of the drugs tested here: Diphtheria-tetanus-acellular pertussis-inactivated poliovirus-Haemophilus influenzae b conjugate-hepatitis B vaccine · Pediarix · Pneumococcal 20-Valent Conjugate Vaccine