Yellow fever was confirmed in laboratory tests by the Institut Pasteur in Dakar, Senegal. WHO and the Ministry of Health began working with partners in the Global Outbreak Alert and Response Network, including UNICEF and Agence de médecine préventive (AMP) to organize a mass vaccination campaign. Vaccination is the most important measure for controlling yellow fever outbreaks. It provides immunity within seven to 10 days in 95% of those vaccinated.
