Immunization, Vaccines and Biologicals

Meningococcal meningitis

Neisseria meningitidis (meningococcus) is a leading cause of bacterial meningitis and septicaemia. Endemic disease occurs worldwide, with outbreaks most frequently occurring in the “Meningitis Belt” of sub-Saharan Africa. There are no reliable estimates of global meningococcal disease burden due to inadequate surveillance in several parts of the world. Invasive meningococcal disease has a very high fatality rate (>50% if untreated) and many survivors develop permanent sequelae. Of the 12 N. meningitidis serogroups identified, A, B, C, X, W135, and Y are responsible for the majority of disease, but serogroup distribution varies by location and time. Meningococcal infections are transmitted through contact with respiratory droplets or secretions.

Currently there are several polysaccharide and conjugate vaccines available for protection from the most common serogroups of meningococcal disease. Polysaccharide vaccines are available in bivalent (A, C), trivalent (A, C, W135), and quadrivalent (A, C, W135, Y) formulations. Conjugate vaccines, which are more immunogenic and can provide herd protection, are available in monovalent (A or C), quadrivalent (A, C, W135, Y), or combination (serogroup C and Haemophilus influenza type b) formulations. There are no vaccines available against serogroup X disease.

In December 2010, a new meningococcal A conjugate vaccine developed through the WHO-PATH Meningitis Vaccine Project was introduced in Africa, reaching over 150 million by the end of 2013.

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 introduce appropriate large scale meningococcal vaccination programmes. 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 travelers at risk of exposure should be vaccinated against the prevalent serogroup(s), and vaccination should be offered to all individuals suffering from immunodeficiency.

Development and testing of universal group B protein-based vaccines is ongoing, with the first product having become available in 2013.

WHO position paper

Prequalified Vaccines

Disease burden and surveillance

Guidelines for national regulatory authorities

Vaccine safety

Immunological basis for immunization series

Disease control programme

Related partner links

Resources

Last updated: 31 March 2014

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