Neisseria meningitidis is a leading cause of bacterial meningitis and sepsis throughout the world. Twelve serogroups have been identified, six of which (A, B, C, W, X and Y) can cause disease and epidemics. Meningococcal meningitis is largely a vaccine preventable disease and several vaccines are available for protection from the most common serogroups causing disease. They are used both for routine immunization and to respond to meningitis epidemics.

Meningococcal vaccines 

Meningococcal polysaccharide vaccines are safe and effective in children and adults but weakly immunogenic in infants, do not induce a booster response, do not provide herd protection and can induce immunologic hypo responsiveness upon repeated vaccination. They are still used for outbreak control and gradually being replaced by polysaccharide-protein conjugate vaccines, which are more immunogenic and effective in preventing nasopharyngeal carriage of the bacteria and thus its transmission. They are available in monovalent (A or C), quadrivalent (A, C, W, Y), pentavalent (A, C, W, Y, X) or combination (serogroup C and Haemophilus influenzae type b) formulations.
Meningococcal meningitis is largely a vaccine preventable disease and several vaccines are available for protection from the most common serogroups causing disease. They are used both for routine immunization and to respond to meningitis epidemics.

Until recently, serogroup A strains were the major cause of epidemic and endemic meningococcal disease in the meningitis belt in sub-Saharan African. The introduction of a meningococcal A conjugate vaccine (MenACV) in belt countries has led to a dramatic reduction in the number of cases due to N. meningitidis A.A significant residual disease burden is now caused by serogroups C, W and X in these epidemic-prone areas. The meningococcal B polysaccharide capsule cross-reacts with human antigens and is poorly immunogenic. Tailored serogroup B vaccines based on the outer membrane vesicles of clonal strains have been developed to control specific outbreaks. Two protein-based vaccines are now available that offer broad protection against serogroup B meningococcal disease. They have also recently been made available in combination with quadrivalent conjugate vaccines.

WHO recommends that countries with high (>10 cases per 100,000 population/year) or intermediate (2-10 cases per 100,000 population/year) endemic rates and/or frequent epidemics of invasive meningococcal disease conduct appropriate large scale meningococcal vaccination programmes. The importance of conducting high quality surveillance and vaccination programme evaluation in these countries is also stressed. 

In addition, WHO recommends that countries of the African meningitis belt introduce one dose of pentavalent meningococcal ACWYX conjugate vaccine (Men5CV) into their routine immunization programme, with a one-off mass-preventive campaign in high-risk countries and countries with high-risk districts.

In countries where the disease occurs less frequently (< 2 cases per 100,000 population/year), meningococcal vaccination is recommended for defined risk groups. Laboratory worker and travellers at risk of exposure should be vaccinated against the prevalent serogroup(s), and vaccination should be offered to all individuals suffering from immunodeficiency. Meningococcal meningitis is an epidemic-prone disease and there is a global emergency meningococcal vaccine stockpile managed through the International Coordinating Group (ICG) for vaccine provision for meningococcal meningitis.