DRC's Ebola Outbreak Is Driven by a Virus Species With Uncertain Vaccine Coverage

The DRC's 2026 Ebola outbreak — 3,973 confirmed cases and 1,801 deaths as of 4 August across 51 health zones — is caused by the Bundibugyo virus species, not the Zaire ebolavirus that dominates most DRC outbreaks. Licensed vaccines and therapeutics were validated against Zaire ebolavirus, leaving their efficacy against Bundibugyo uncertain. Responders face this gap in an active conflict zone with cross-border spread into Uganda.