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.
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
Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
San Miguel de Tucumán, Tucumán Province, Argentina
San Miguel de Tucumán, Tucumán Province, Argentina
Buenos Aires, Argentina