Maternal Group B Streptococcus Vaccination: A Three-Country European Consortium to Improve Surveillance and Data Readiness

Background: Group B Streptococcus (GBS) is a common gut coloniser, yet it can cause serious disease in pregnant women, newborns, and in adults with predisposing conditions. Estimates suggest that approximately 20 million pregnant women are colonised with GBS, and 394,000 cases of invasive disease occur in infants every year, but there are many data gaps. Several countries lack robust data, leading to likely underestimation of the true disease burden, notably for GBS-associated stillbirths and preterm births. Objective: Recent progress in the development of maternal GBS vaccines adds urgency to the need for comprehensive surveillance data. The aim of this study is to describe advances in routine health information systems and record linkage offer new opportunities for robust monitoring and research on GBS outcomes, both before and after vaccine roll-out. Approach: This review article identifies crucial research gaps, proposes priority outcomes that should be monitored, and highlights opportunities to use routine data from three European countries (Denmark, the Netherlands, the United Kingdom) to harmonise data and strengthen the evidence base to inform national GBS vaccine policy decisions. Conclusion: Strengthening and harmonising routine data collection across Europe and globally will be essential to maximize and measure the benefits of a maternal GBS vaccination. Keywords: Group B Streptococcus , maternal vaccines, health registries