Novel vaccine candidates against meningococcal disease
Minor proteins as the basis for vaccines against MenB
Dr Ana Cehovin, Dr Vladimir Pelicic
- Start Date:
01 January 2008
Imperial College, London, UK
Meningococcal disease strikes without warning and can kill a healthy person of any age within hours of the first symptoms. It is most likely to affect babies, young children and adolescents. New vaccines to prevent this disease, which is a grave concern to parents and healthcare providers, are urgently needed.
Successful meningitis vaccines developed so far, including those against Hib and meningococcal C disease rely on a technique that involves linking a fragment of the bacterial sugar coat to a protein, resulting in a 'conjugate'. People immunised with conjugate vaccines can destroy any bacteria that have the same kind of sugar coat as the vaccine. However, the sugar coat of meningococcal B bacteria does not provoke an immune response, so this approach cannot be applied to MenB vaccine development in a straightforward way. The search for a MenB vaccine has focused on other structure on the surface of MenB bacteria, but these are extremely variable, so it is difficult to identify vaccine candidates that are likely to provide broad cross-protection against the many different sub-strains.
An ideal vaccine would target molecules that are present on the surface of every, or at least the majority of meningococcal strains, hence conferring broad protection. Scientists at Imperial College have recently identified potential targets in minor protein components of the hair-like surface structures the bacteria use to hook themselves onto the cells lining the human nose and throat. These proteins are present in all clinical isolates of meningococcal bacteria. Their vaccine potential will be tested during this project. In the future, these proteins could be part of a new vaccine able to defeat meningococcal meningitis and septicaemia, including MenB disease which continues to circulate unchecked by any available vaccine.