Group B Streptococcus: global incidence and vaccine development

Key Points Streptococcus agalactiae or Group B Streptococcus (GBS) is an important pathogen that affects neonates, peripartum women and the elderly worldwide. Prenatal maternal screening for GBS and antibiotic treatment has reduced the rate of neonatal GBS disease but the best long-term solution for control of the disease is vaccination. Several GBS vaccine candidates have been developed, including conjugate vaccines prepared by linking purified capsular polysaccharide to proteins. Conjugate vaccines have been prepared against all nine currently identified GBS serotypes. Human clinical trials with several conjugate vaccines have successfully completed phase I and II testing with promising results. In addition, a type III conjugate vaccine has been found to be safe and immunogenic in pregnant women. Reverse vaccinology has revealed new GBS protein antigens that are immunogenic and efficacious in preclinical studies involving mice. Further advances in GBS vaccine development are likely through combining genomics with newer proteomic technologies. Group B Streptococcus (GBS) is a pathogen of worldwide significance, and although prophylactic measures have reduced the number of infections, development of a vaccine remains an important goal. Here, the authors review the incidence of GBS and how new technologies are being applied in the search for a globally effective vaccine. An ongoing public health challenge is to develop vaccines that are effective against infectious diseases that have global relevance. Vaccines against serotypes of group B Streptococcus (GBS) that are prevalent in the United States and Europe are not optimally efficacious against serotypes common to other parts of the world. New technologies and innovative approaches are being used to identify GBS antigens that overcome serotype-specificity and that could form the basis of a globally effective vaccine against this opportunistic pathogen. This Review highlights efforts towards this goal and describes a template that can be followed to develop vaccines against other bacterial pathogens.