Three Bundibugyo vaccines move toward efficacy trials in Congo as the epidemic passes 3,000 deaths
The World Health Organization says the Bundibugyo outbreak declared in the Democratic Republic of the Congo on May 15, 2026 has passed 6,000 reported cases and reached 3,000 deaths. No licensed vaccine exists for this species. Candidates from Moderna and the University of Oxford are in safety trials in the United Kingdom and Canada, while Ervebo, licensed against the Zaire species, is going to frontline health workers in Kisangani under trial protocols. Efficacy trials for all three are targeted for October or November.
Science··Midday
A plan to test three vaccines in one trial
The species behind the outbreak in the Democratic Republic of the Congo is Bundibugyo, and no licensed vaccine exists against it. WHO Director-General Tedros Adhanom Ghebreyesus said two new vaccines against Bundibugyo virus are in safety trials in the United Kingdom and Canada: the messenger-RNA candidate from Moderna and the candidate from the University of Oxford. The third candidate is Merck's Ervebo, licensed against the Zaire species. Kate O'Brien, who runs vaccines at WHO, described a plan to test several vaccines in a single trial, with Ervebo expected to enter first as the already licensed candidate. The day before the briefing WHO published emergency guidance on the use of the licensed Zaire ebolavirus vaccine during outbreaks of Bundibugyo. Whether Ervebo protects against this species is what the trial is meant to establish. WHO is working with partners to take all three vaccines into efficacy trials in the Democratic Republic of the Congo, with October or November the target.[1], [2]
The scale of the epidemic and the weight of Ituri
The outbreak was declared on May 15, 2026. Tedros said it has passed 6,000 reported cases and reached 3,000 deaths, and now affects 60 health zones in six provinces. Ituri province carries 85 per cent of cases and 88 per cent of deaths. Most deaths still happen in communities rather than in treatment centres, many of the dead are not being buried safely, and many were not on any list of known contacts, which WHO treats as a sign of transmission chains it has not yet found. The organisation places the epidemic inside the humanitarian picture of a region that has lived through decades of conflict, displacement, poverty and hunger, and describes local mistrust alongside that picture.[1], [2]
Vaccination in Kisangani, more laboratories and more beds
Some 16,250 doses of Ervebo arrived in July, and vaccination of frontline medical workers began in Kisangani, the capital of Tshopo province, under trial protocols. WHO has shipped more than 330 tonnes of emergency supplies and deployed more than 300 experts. Laboratory capacity has grown from one national reference laboratory to a network of 24, and testing capacity to 3,000 tests a day. Treatment and isolation capacity has reached more than 1,300 beds across 49 treatment facilities, with a plan to triple that to 3,000 beds within three months. A trial of two treatments called PARTNERS has enrolled more than 300 Ebola patients, and a separate trial is testing the antiviral obeldesivir among high-risk contacts. The government-led plan for the next six months carries an ask of 1.3 billion dollars.[1], [2]
