1. Healthy adults (male and female) at enrollment who are determined by medical history,
physical examination, and clinical judgment of the investigator to be eligible for
inclusion in the study.
2. Participants who were enrolled in the C1091001 study, received GBS6, and completed the
1-month blood draw.
1. Pregnant female participants; breastfeeding female participants; positive urine
pregnancy test for women of childbearing potential (WOCBP) at Visit 1 (prior to
vaccination); and WOCBP who are, in the opinion of the investigator, sexually active
and at risk for pregnancy and fertile men and WOCBP who are unwilling or unable to use
effective methods of contraception as outlined in this protocol from the signing of
the informed consent until at least 3 months after the last dose of investigational
2. Acute or chronic medical or psychiatric condition or laboratory abnormality that may
increase the risk associated with study participation or investigational product
administration or may interfere with the interpretation of study results and, in the
judgment of the investigator, would make the participant inappropriate for entry into
this study. Chronic medical conditions include human immunodeficiency virus, chronic
hepatitis B virus (HBV) infection (HBV surface antigen positive), and/or hepatitis C
3. History of severe adverse reaction and/or severe allergic reaction (eg, anaphylaxis)
to any vaccine.
4. History of microbiologically proven invasive disease caused by group B streptococcus
5. Previous vaccination with any licensed or investigational group B streptococcus
vaccine (other than GBS6), or planned receipt during the participant's participation
in the study (through 6-month telephone call).