WHO recommends Ervebo trial in DR Congo Ebola outbreak

The World Health Organization said Friday that scientists should start a full human trial of the only licensed Ebola vaccine to see whether it can protect people against a rare and deadly strain now spreading in the Democratic Republic of Congo.

The recommendation follows genetic confirmation that the virus causing the new outbreak belongs to the so-called “Bundibugyo ebolavirus” species, for which the vaccine—Ervebo—was not originally tested. Bundibugyo Ebola has killed close to 40 per cent of people infected in past flare-ups, compared with about 50 per cent for the Zaire strain that Ervebo was designed for. The current DR Congo outbreak is the country’s eleventh since 1976 and the first to involve Bundibugyo.

The WHO’s Strategic Advisory Group of Experts on Immunization said existing data suggest Ervebo may still offer some protection, but lab tests are not enough. A human trial would give real-world evidence. The group wants researchers to begin a ring-vaccination study as soon as possible, enrolling people at highest risk such as contacts of confirmed cases and health workers. They also urged rapid roll-out of next-generation vaccines that target Bundibugyo specifically.

DR Congo’s health ministry, the Africa Centres for Disease Control, and global partners including Gavi and the U.S. Centers for Disease Control are now expected to fast-track ethical approvals and funding. If the trial shows Ervebo works, it could be quickly deployed in future outbreaks and save lives in central Africa, where Ebola hotspots often emerge in remote, hard-to-reach areas. Failure to confirm protection would force a scramble for other experimental shots, leaving communities vulnerable while scientists race to catch up.