The World Health Organisation (WHO) has recommended that a vaccine called Ervebo be prioritised for a randomised clinical trial against Bundibugyo virus disease in the Democratic Republic of Congo (DRC). The Bundibugyo virus causes Ebola disease. The Bundibugyo virus disease outbreak in the DRC is the first of its kind in the country. However, the experts stressed that the vaccine’s effectiveness against Bundibugyo virus disease and its ability to prevent transmission have not been established. WHO said a vaccine specifically developed against the Bundibugyo virus would remain the preferred option, although preliminary data on such candidates are currently unavailable.