[Controlled tests of anti-meningococcal polysaccharide A vaccine in the African Sahel area (Upper Volta and Mali) ].

After the first tests of this vaccine in Egypt (1972) and in the Sudan (1973), two controlled tests in the field were performed in two high-risk areas for meningitis: --firstly, in the region of Koudougou (Upper-Volta), in November-December 1973 (17,300 vaccines). Its major aim was to solve operational and logistical problems; --secondly, in the Koutiala (Mali) area, according to a very strict schedule, in November-December 1975 and December 1975 (37,979 vaccines). The complete innocuousness of the vaccine was proven and excellent seroconversion was observed after its administration. On the individual level, it was confirmed that the vaccine ensures excellent protection for a period of at least three years. This new prophylactic weapon inspires the authors to suggest a new strategy in the fight against meningitis epidemics caused by meningococcus in the African Sahel area, taking into account the current increase there in serogroup C, against which there is also a vaccine whose efficacy has already been demonstrated.