Why does Ebola keep coming back?

In May 2026, the World Health Organization declared an Ebola outbreak in western Africa a public health emergency of international concern. Within days, hundreds of cases had been recorded in the Democratic Republic of Congo, raising fears that the virus could spread further across the region.

Ebola has been causing outbreaks for nearly 50 years, but despite advances in vaccines and treatments, the disease continues to return. But why is it so difficult to treat and contain?

Contributors Syra Madad, infectious disease epidemiologist at the Harvard Belfer Centre, US Hypolite Muhindo Mavoko, professor of tropical medicine at the University of Kinshasa, the Democratic Republic of Congo Amanda Rojek, associate professor of health emergencies at the University of Oxford, UK Julienne Anoko, risk communication and community engagement officer at the World Health Organization Regional Office for Africa, Kenya

Presenter: Tanya Beckett Producer: Matt Toulson Researcher: Amelia Cox Technical producer: Nicky Edwards Editor: Tom Bigwood Production management: Phoebe Lomas and Liam Morrey

(Photo: Ebola awareness banner in Democratic Republic of the Congo. Credit: Glordy Murhabazi/Getty Images)