Beyza Binnur Donmez
07 August 2026•Update: 07 August 2026
The World Health Organization (WHO) experts on Friday recommended prioritizing the licensed Ebola vaccine Ervebo for evaluation in a randomized clinical trial amid the ongoing Bundibugyo virus disease outbreak in the Democratic Republic of the Congo.
The WHO said in a statement that its Technical Advisory Group on candidate vaccine prioritization made the recommendation after reviewing new preliminary data showing that Ervebo offered "some level of cross-protection" against Bundibugyo virus disease in animal studies, particularly against death.
Ervebo is the only licensed Ebola vaccine, but it is approved against Ebola virus disease caused by the Zaire ebolavirus rather than Bundibugyo virus.
The advisory group found "no safety concerns" with potentially using the vaccine during a Bundibugyo outbreak in a trial in which contacts of cases are vaccinated.
The experts, however, stressed that Ervebo's effectiveness against Bundibugyo disease and transmission still needs to be demonstrated through research.
They said a vaccine specifically targeting Bundibugyo would remain the preferred option, though preliminary data on candidate vaccines are not yet available.
The WHO convened its advisory groups after declaring the Congo outbreak a Public Health Emergency of International Concern on May 16. On July 31, the members of the advisory group met for the third time to review new data.
The group had previously recommended that Ervebo not be used outside carefully designed research settings until its performance against Bundibugyo virus could be assessed.
