Bundibugyo virus: the Orthoebolavirus species behind the current outbreak

Background

The World Health Organization describes Bundibugyo virus disease as a severe Ebola disease caused by the Bundibugyo virus, one of the Orthoebolavirus species. The outbreak that has now reached five countries was declared on 15 May 2026, and the WHO page lists the Democratic Republic of the Congo, Kenya, Nigeria, Uganda and France among the countries that have reported cases since then. The WHO page states that no approved vaccines or specific treatments currently exist for Bundibugyo virus disease. A pivotal Phase 2/3 vaccine trial against Bundibugyo virus, named TUMAINI, was launched on 23 October, with the first participants enrolled in Bunia. Contact tracing is central to control: in the Democratic Republic of the Congo the follow-up rate was 79.7%, below the target of 95.0%. The WHO advises against any restriction of travel to, or trade with, affected countries.