Development of a novel vaccine against meningococcal bacteria.

Meningococcal bacteria are the most common cause of life-threatening meningitis and septicaemia in the UK and Ireland, and an important cause of meningitis worldwide.  Many meningococcal strains can be prevented from causing disease. The men C vaccine has dramatically reduced cases of the C-strain since it was introduced into the UK and Ireland in 1999/2000. A MenACWY vaccine has been available in the US and Canada for some years and similar vaccines are in development. A men A vaccine will soon be introduced into countries in the African meningitis belt.

In contrast, development of a vaccine against the meningococcal B strain has proved very difficult.

All successful meningitis vaccines so far have been based on the 'sugar' coat of the bacteria. The sugar coat of the Group B meningococcal bacteria is quite different to other strains, as it does not produce an immune response, so the same approaches cannot be applied to developing a B vaccine in a straightforward way. Group B bacteria are also extremely variable, which makes it difficult to find a vaccine that protects against all sub-strains.

Vaccines based on molecules found on the surface of the bacteria have so far not worked very well in infants and young children (who are the highest risk group). The scientists on this project have been developing a vaccine candidate based on a de-toxified version of molecules in the outer wall of the bacteria (in this case, a fat molecule linked to a sugar which is among the ingredients that makes the bacteria's toxin). We hope that this will be both safe and effective at preventing the disease.

The important next step in development of this vaccine is to find out whether it can produce the right sort of immune response in mice and also special immune system cells taken from human volunteers. This is what we hope this project will achieve.