Meningococcal meningitis
The meningitis vaccine project
Following major epidemics in the 1990s, there was a crucial demand from the African meningitis belt countries to develop an affordable conjugate vaccine to prevent future epidemics. This led to the establishment of the Meningitis Vaccine Project (MVP) [see link below], a partnership between PATH and WHO, funded by a Bill & Melinda Gates Foundation grant in 2001.
The first meningococcal A conjugate vaccine, MenAfriVac, developed through the Meningitis Vaccine Project was introduced nationwide in Burkina Faso, and in selected areas of Mali and Niger in December 2010, through mass vaccination campaigns among 1 to 29 year-olds. Subsequently, by the end of the 2011 meningitis season, these countries reported the lowest number of confirmed meningitis A cases ever recorded during an epidemic season.
The vaccine has several advantages over existing polysaccharide vaccines: it induces a higher and more sustainable immune response against group A meningococcus; it reduces the carriage of the bacteria in the throat and thus its transmission; as a result it is expected to confer long-term protection not only for those who receive the vaccine, but also for family members and others who would otherwise have been exposed to meningitis; it is expected to be particularly effective in protecting children under two years of age, who do not respond to conventional polysaccharide vaccines; and it is available at a lower price than other meningococcal vaccines.
Clinical trials related to licensing and prequalification of MenAfriVac for use in 1 to 29 year-olds have been successfully completed in India, Mali, Senegal, and the Gambia. A Phase II trial to evaluate the immunogenicity and safety of the vaccine in infants in Ghana is scheduled for completion in 2012. A Phase III clinical study, expected to start in Mali in early 2012 will provide the complementary data to support a policy recommendation for a pediatric indication by 2014.