Use of capsular polysaccharide-tetanus toxoid conjugate vaccine for type II group B Streptococcus in healthy women

An estimated 15% of invasive group B streptococcal (GBS) disease is caused by type II capsular polysaccharide (II CPS), In developing a pentavalent va ccine for the prevention of GBS infections, individual GBS CPSs have been c oupled to tetanus toroid (TT) to prepare vaccines with enhanced immunogenic ity, Type II GBS (GBS II) vaccine was created by direct, covalent coupling of IT CPS to TT by reductive amination. In 2 clinical trials, 75 healthy no npregnant women 18-45 years old were randomized to receive II CPS-TT (II-TT ) conjugate (dose range, 3.6-57 mu g of CPS component) or uncoupled II CPS vaccine. Both vaccines were well tolerated, II CPS-specific IgG serum conce ntrations (as well as IgM and IgA) peaked 2 weeks after immunization, being significantly higher in recipients of conjugated vaccine than in recipient s of uncoupled CPS, Immunological responses to conjugate were dose dependen t and correlated with opsonophagocytosis in vitro. These results support in clusion of II-TT conjugate when preparing a multivalent GBS vaccine.