History of meningococcal vaccines and their serological correlates of protection

► Vaccines based on capsular polysaccharides protect against most meningococcal disease. ► Glycoconjugate vaccines improve polysaccharide immunogenicity providing protection in infants. ► SBA level is the established correlate of protection used to license polysaccharide vaccines. ► Novel vaccines based on protein antigens designed to improve coverage are undergoing licensure. ► SBA is proposed as the correlate of protection for protein antigens but remains to be validated.