West Africa is experiencing the largest, most severe and most complex outbreak of Ebola virus disease in history. Ebola outbreaks can be contained using available interventions like early detection and isolation, contact tracing and monitoring, and adherence to rigorous procedures of infection control. However, a specific treatment or vaccine would be a potent asset to counter the virus.

The current Ebola virus disease (EVD) outbreak is believed to have begun in Guinea in December 2013. This outbreak now involves community transmission in Guinea, Liberia and Sierra Leone and recently an ill traveller from Liberia infected a small number of people in Nigeria with whom he had direct contact.

On 8 August 2014, WHO declared the Ebola virus disease outbreak in West Africa a Public Health Emergency of International Concern (PHEIC) in accordance with the International Health Regulations (2005).