Early-onset group B streptococcal disease in African countries and maternal vaccination strategies

Area of Science:

• Obstetrics and Gynecology
• Neonatal Medicine
• Vaccinology

Background:

• Invasive group B streptococcal (GBS) disease is a leading cause of perinatal bacterial infection in newborns, with a disproportionately high burden in African countries.
• Intrapartum antibiotic prophylaxis is often not feasible in sub-Saharan Africa, leading to severe outcomes: nearly 25% of affected newborns die, and 10% of survivors experience neurodevelopmental impairment.

Purpose of the Study:

• To evaluate the potential of a maternal GBS vaccine as a pragmatic and cost-effective preventative strategy for invasive GBS disease in African infants.
• To outline the necessary steps for vaccine licensure, including demonstrating safety and identifying immunological correlates of protection.

Main Methods:

• Review of current GBS disease burden in sub-Saharan Africa.
• Overview of ongoing phase II clinical trials for hexavalent polysaccharide protein conjugate and Alpha family surface protein GBS vaccines.
• Discussion of requirements for vaccine licensure and subsequent phase IV effectiveness studies.

Main Results:

• Maternal GBS vaccination is proposed as a key strategy to reduce infant GBS disease burden in Africa.
• Phase II clinical trials are underway for promising GBS vaccine candidates.
• Demonstrating safety and immunological correlates is crucial for vaccine licensure.

Conclusions:

• A maternal GBS vaccine represents a critical, cost-effective intervention for preventing invasive GBS disease in African newborns.
• Future research will focus on vaccine effectiveness, including its impact on neonatal infections, mortality, and stillbirths.