Vaccines to prevent neonatal GBS infection.

Group B Streptococcus (GBS) remains the leading bacterial cause of neonatal sepsis and meningitis in the United States. Although antibiotic prophylaxis has decreased the infection rate, the best long-term solution lies in the development of effective vaccines. The GBS capsular polysaccharide (CPS) is a major target of antibody-mediated immunity. While antibody to CPS is protective, uncoupled CPS is variably immunogenic in humans, a finding that led to the development of GBS CPS-protein conjugate vaccines. GBS CPS-protein conjugate vaccines of all clinically important serotypes have been produced and tested in animals. Mice and baboons immunized with CPS conjugates transplacentally transferred functionally active GBS-specific IgG to their offspring. Phase 1 and phase 2 clinical trials have shown that GBS conjugate vaccines are safe, well-tolerated and immunogenic in healthy adults. Moreover, human antibodies elicited by the conjugate vaccines are functionally active both in vitro and in animal models of invasive GBS disease. Copyright 2002 Elsevier Science Ltd.