The West African Ebola Epidemic (2013–2016)

The largest Ebola outbreak in history, which spread through Guinea, Liberia, and Sierra Leone, killed more than 11,000 people, exposed weaknesses in global outbreak response, and led to the development of the first licensed Ebola vaccine.

Events

The Virus Spreads to Sierra Leone and Liberia

Sierra Leone confirmed its first Ebola cases in late May, followed by Liberia. By mid-2014 the epidemic spanned three countries with porous borders and health systems weakened by years of conflict, and traditional burial practices involving touching the dead continued to amplify transmission.

Location: Kailahun, Sierra Leone

WHO Declares a Global Health Emergency

With cases surging in Monrovia and Freetown, the World Health Organization declared the Ebola epidemic a Public Health Emergency of International Concern. The declaration came after criticism that the global response had been slow and that WHO itself had acknowledged delayed escalation.

Location: Geneva, Switzerland

Community Distrust and Attacks on Responders

Residents of the West Point neighborhood of Monrovia attacked an Ebola holding center, protesting the quarantine of their community and distrusting outbreak statistics. Rumors and denial shaped the epidemic's course throughout the region, and responders were sometimes met with hostility or violence.

Location: Monrovia, Liberia

Ebola Reaches the United States and Europe

A Liberian man, Thomas Eric Duncan, was diagnosed with Ebola in Dallas and died on October 8; two nurses who treated him were infected and recovered. Imported cases and subsequent infections of healthcare workers in Spain and the UK triggered intense public debate in Western countries about screening and quarantine policies.

Location: Dallas, Texas, USA

An Effective Vaccine Emerges Mid-Outbreak

The Lancet published interim results of the rVSV-ZEBOV ring-vaccination trial in Guinea, showing no cases among those vaccinated immediately, versus delayed clusters. The trial had been organized during the outbreak itself; the vaccine was later licensed (as Ervebo) in Europe in 2019 and in the United States.

Location: Conakry, Guinea

Countries Declare the End of Transmission

Countries Declare the End of Transmission

Sierra Leone was declared Ebola-free in November 2015, following similar declarations for Liberia in May and preceding Guinea's in December. Flare-ups occurred after each declaration, and Liberia was declared Ebola-free three separate times before the epidemic fully subsided.

Location: Freetown, Sierra Leone

WHO Declares the End of the Epidemic and Its Flare-Ups

WHO Declares the End of the Epidemic and Its Flare-Ups

WHO declared the end of the West African Ebola epidemic's final flare-ups, closing an outbreak that had caused about 28,600 cases and more than 11,000 deaths — more than all previous Ebola outbreaks combined. The epidemic prompted reforms in outbreak response and research on vaccines and therapeutics.

Location: Geneva, Switzerland