The World Health Organization is advancing plans to launch a clinical trial of an Ebola vaccine in the Democratic Republic of Congo, where a fast-moving outbreak has already killed more than 2,000 people.
As of this week, the epidemic in DRC’s Ituri province — near the borders with Uganda and South Sudan — has topped 4,500 confirmed cases and 2,060 deaths, making it the second-largest Ebola epidemic on record and one that is spreading faster than previous ones. “At its current pace, it’s on track to eclipse the West African Ebola outbreak of 2014–2016,” WHO Director-General Tedros Adhanom Ghebreyesus said.
The planned trial
The first vaccine to be tested is Merck’s Ervebo, which targets the Ebola Zaire species. WHO is submitting the Phase 3 protocol to DRC regulatory and ethics committees for approval. Rather than the “ring vaccination” approach used before, the trial would individually randomize known contacts of cases to vaccine or placebo — which WHO’s Vasee Moorthy said is “more efficient.”
A broader pipeline
Other candidates are also moving: the Oxford Vaccine Group with the Serum Institute and IAVI are working on vaccines for the Bundibugyo strain, and Moderna has a Phase 1 mRNA Ebola vaccine trial underway in Canada, with early results expected in September 2026. For now, the priority is getting a proven tool into a worsening emergency as quickly as regulators allow.