The Centre Pasteur of Cameroon, Annex of Garoua, studied since 2007 méningococcus of meningitidis in the North of Cameroon. The serogroup A méningococcus completely seem to have disappeared with the profit from the serogroup W135 méningococcus. Current measurements of answers to an epidemic, based between others on reactive vaccination will have to take into account these new data to remain effective. Trivalent vaccine ACW135, placed at the disposal by WHO, should logically be able to be used in the event of epidemic, under reserve of an identification of the germ by a laboratory. The diffusion of the results of the circulation of serogroup W135 méningococcus supported vaccination by the tetravalent vaccine, but this one remains very expensive and, so held for a negligible minority of the population of North-Cameroon. It is part from now on of the recommendations to the travellers.