WHO and DRC Advance Talks to Launch Phase 3 Ervebo Trial Against Bundibugyo

STAT News reported on 12 August 2026 that WHO and DRC authorities are advancing talks to launch a Phase 3 clinical trial testing whether vaccines can help contain the Bundibugyo outbreak, following WHO's 7 August recommendation. Merck's Ervebo (rVSV-ZEBOV) — licensed for Zaire ebolavirus, with roughly 84% effectiveness against that species in prior field studies and a roughly 500,000-dose stockpile available — would be the first candidate, with the trial design randomizing individual contacts of cases to vaccine or placebo. Bundibugyo-specific candidates from Oxford Vaccine Group, Moderna, and IAVI may be added later. WHO Director-General Tedros Adhanom Ghebreyesus said: 'It's already the second-biggest Ebola epidemic on record, and it's moving faster than any previous Ebola outbreak.'