Meningococcal B vaccine: The journey from research to real world experience.

Introduction: Neisseria meningitidis serogroup B (MenB) is the most common cause of bacterial meningitis in many industrialized countries and occurs at any age. The highest incidence is in infants aged <1 year, followed by children and adolescents. Four-component MenB vaccine (4CMenB, Bexsero) is the only MenB vaccine authorized for use in all age-groups. Experience with 4CMenB is growing as it is implemented in different countries/age-groups encompassing university students, children, adolescents, and infant mass vaccination programs. Areas covered: An update of recently available data describing the mechanism of immunogenicity of 4CMenB and real-world evidence of vaccine effectiveness and disease impact. We discuss the appropriate age for vaccination to maximize population impacts. Expert commentary: Invasive meningococcal disease is uncommon and sufficiently powered efficacy studies were not feasible during 4CMenB development. Additionally, several thousand genetically diverse invasive MenB strains circulate globally, varying widely in surface protein expression. This posed significant challenges in predicting clinical protection with MenB vaccines. Five years of 4CMenB use post-licensure confirm the clinical benefit of vaccination as predicted during development. Preliminary evidence suggests an extended impact on other meningococcal serogroups and Neisseria gonorrhoeae.