Meningococcal disease: a review on available vaccines and vaccines in development.

Meningococcal disease continue to have a major public health impact in many countries. Five major groups of Neisseria meningitidis (A, B, C, Y and W135) are responsible for most meningococcal diseases. Plain polysaccharides vaccines for Neisseria meningitidis groups A, C, Y and W-135 have been in use for approximately 20 years, both to prevent invasive disease in high-risk population and to control disease outbreaks. However, these conventional meningococcal vaccines induce a relatively short-lasting T-cell independent immune response, are not effective in children under two years of age and can induce hyporesponsiveness. New meningococcal group C conjugate vaccines have since been developed, which offer solid advantages over the currently licensed plain polysaccharide vaccines. Tetravalent serogroup A, C, Y and W135 meningococcal vaccines are under development and one has already been licensed. There is still no universal vaccine available against the serogroup B, which is a major cause of invasive disease. This report summarises the different approaches to the development of vaccines against the pathogenic meningococci.