ABSTRACT
Outbreaks of Neisseria meningitidis recur frequently in the African Sahel where they are responsible for high mortality and morbidity; especially in children. An effective vaccine has been in existence for more than 30 years; but despite this; the control of epidemics has failed. Moreover; the geographical distribution of N. meningitidis seems to be increasing; perhaps because of climate change but also because of the economic crisis which prevails throughout much of Africa leading to population movements and the breakdown of essential services. Although alarming; the emergence of new serogroups in recent epidemics (such as serogroups X and W135) should not mask the fact that serogroup A remains the most common meningococcal isolate from meningitis cases and is therefore the most significant target for control. The development of a low-cost conjugate meningococcal vaccine should support a strategy of preventive immunization; as this strategy is one that appears most effective to control this plague