Endemic and epidemic meningococcal disease constitutes a major public-health problem in African
countries of the 'meningitis belt' where incidence rates of the disease are many-fold higher (up to 25
cases per 100,000 population) than those in industrialized countries, and epidemics of meningococcal
disease occur with rates as high as 1,000 cases per 100,000 people. Using the precedent established
during the licensing of conjugate vaccines against
Haemophilus influenzae
type b and serogroup C meningococci and components of currently-licensed meningococcal polysaccharide vaccines, new
meningococcal conjugate vaccines will likely be licensed using immunological endpoints as surrogates
for clinical protection. Post-licensure evaluation of vaccine effectiveness will, therefore, be of
increased importance. One vaccine being developed is the serogroup A meningococcal (Men A) conjugate
vaccine produced by the Meningitis Vaccine Project (MVP), a partnership between the World
Health Organization and the Program for Applied Technology in Health. This vaccine will likely be
the first meningococcal conjugate vaccine introduced on a large scale in Africa. This paper summarizes
the general steps required for vaccine development, reviews the use of immunogenicity criteria
as a licensing strategy for new meningococcal vaccines, and discusses plans for evaluating the impact
of a meningococcal A conjugate vaccine in Africa. Impact of this vaccine will be measured during a
vaccine-demonstration project that will primarily measure the effectiveness of vaccine. Other studies
will include evaluations of safety, vaccine coverage, impact on carriage and herd immunity, and prevention-
effectiveness studies.
