An Ebola outbreak in the Democratic Republic of Congo has killed more than 80 as authorities warned there was no vaccine for the strain in a crisis that the World Health Organization declared an international health emergency on Sunday.

A total of 88 deaths and 336 suspected cases of the highly contagious haemorrhagic fever have been reported, the Africa Centres for Disease Control and Prevention (CDC Africa) said in an update on Saturday.

The Geneva-based WHO said early on Sunday the outbreak caused by the Bundibugyo strain of Ebola constituted a “public health emergency of international concern” – the second-highest level of alert under international health regulations.

The global health body warned the true scale of the number of cases and spread was not clear but stopped short of declaring a pandemic emergency, the highest alert level introduced in 2024.

Medical aid group Medecins Sans Frontieres (MSF) said it was preparing a “large-scale response”, calling the rapid spread of the outbreak “extremely concerning”, in warnings echoed by authorities.

“The Bundibugyo strain has no vaccine, no specific treatment,” DR Congo’s Health Minister Samuel-Roger Kamba said.