Meningitis, a disease responsible for thousands of deaths in Africa, is currently spreading in several West African countries. While ensuring a quick access to treatment for those who are already sick, Médecins Sans Frontières (MSF) is proceeding to conduct mass vaccination campaigns in Nigeria and Niger and is closely following up the situation in other countries in the region. MSF is planning to vaccinate between four and five million people against meningitis. Dozens of MSF teams are mobilized, in cooperation with the Ministries of Health, to respond to the meningitis epidemic. The teams must ensure treatments are easily accessible at the local level for the people who present symptoms of meningitis; they are also acting to contain the epidemic by vaccinating the population at risk in the areas where the epidemic or alert threshold has been reached. Vaccination in populated urban centres is the top priority in order to prevent the spread of meningitis. Epidemics are moving fast, so good reactivity is required. MSF has sent 80 MSF international workers to Niger, 98 to Nigeria, and has hired hundreds of people locally. Meningitis, a massive and deadly threat Meningitis is a contagious and potentially fatal infection of the brain membrane. The current epidemics in West Africa are caused by strain A of the Neisseria meningitis bacterium, the most frequent strain. Without treatment, bacterial meningitis can kill up to 50 per cent of the people who present the clinical symptoms of the disease. Most of the deaths occur within 48 hours. In order to make treatment available to patients as early as possible, MSF teams are providing meningitis treatment in local health centres and referring complicated cases to hospitals. Epidemic spread across northern Nigeria The 31 surveillance teams working have so far recorded 20,448 cases, along with 694 deaths, in these states. The relatively low fatality rates reveal that people are receiving appropriate, effective and timely treatment.  In close partnership with the Ministry of Health (federal and state levels), MSF teams are vaccinating and treating people in nine states. The total population of the area is 38 million. There are 77 MSF teams, together with health ministry workers, carrying out the mass vaccination campaign. So far, around 700,000 people have been immunized in the most affected states of Jigawa, Katsina and Sokoto. New vaccination campaigns are going on or to begin soon for two million people in Jigawa, Bauchi, Gombe, Kaduna, Kebbi, Sokoto and Zamfara states. Teams are currently working on defining the next priorities. Vaccinations are being prepared for 270,000 additional people. In total, if all vaccinations are carried out, more than three million people will be vaccinated by MSF during the meningitis epidemic in Nigeria. Nigeria’s Federal Ministry of Health has supplied 2.3 million doses of meningitis vaccine. Epidemic spread across southern Niger MSF emergency staff have arrived to reinforce the teams who were already working in nutritional and medical programs in the country. In close partnership with the Ministry of Health (national and regional level), MSF has already started vaccination campaigns in the region of Zinder, Maradi and Dosso. The plan is to vaccinate a total of more than two million people, mostly in the Maradi and Zinder regions. In the Maradi region, 1,428 people suffering from meningitis have been reported by the Ministry of Health since the beginning of the year, among whom 44 have died. Beside the essential treatment of sick patients, MSF teams, supporting Ministry of Health staff, have vaccinated 140,000 people in the city of Maradi. As the epidemic is rapidly moving, MSF has launched vaccination campaigns in Madarounfa and Tessaoua districts, and will start working soon in Aguié district. The total target population for this vaccination is estimated to be around 900,000 people. In the Zinder region, MSF mobile teams are supporting health units to provide medical care to meningitis patients in all areas where there are cases. In parallel, 60 vaccination teams are going to cover four districts, mostly in rural areas. More than 270,000 people have already been vaccinated and campaigns are ongoing. Around one million people should be vaccinated by the end of April. Regional scourge In Burkina Faso, Chad and Cameroon, teams are monitoring the situation because of an increase of meningitis cases in those countries.