Background Maternal group B streptococcus (GBS) serotype-specific capsular antibody
concentrations are correlated with susceptibility to neonatal GBS invasive disease. Maternal
immunisation against GBS during pregnancy might protect infants across the period of
susceptibility to invasive disease, but no licensed vaccine exists. This study assessed the
safety and immunogenicity of a CRM 197-conjugated trivalent GBS vaccine in non-pregnant
and pregnant women, and antibody transfer to their infants. Methods We did a phase 1b/2 …

Background This study evaluated the safety and immunogenicity of an investigational
trivalent group B streptococcus (GBS) vaccine in US pregnant women, transplacental
serotype-specific antibody transfer and persistence in infants, and serotype-specific
antibodies in breast milk. Methods This randomized, observer-blind, placebo-controlled trial
administered one dose of trivalent GBS vaccine (n= 49) or placebo (n= 26) to healthy
pregnant 18–40-year-old women at 24 0/7–34 6/7 weeks' gestation. Women were enrolled …