The role of immune correlates of protection on the pathway to licensure, policy decision and use of group B Streptococcus vaccines for maternal immunization: considerations from World Health Organization consultations

•There is a major public health need for GBS vaccines for maternal immunization.•Important obstacles lie in the way of a pivotal clinical efficacy trial for licensure.•A vaccine development pathway based on an immune correlate of protection is envisaged.•Key considerations and priority activities for success are presented, based on WHO consultations.