WHO advises against routine use of Ervebo vaccine for Bundibugyo virus outbreak, recommends research rather than programmatic deployment (iris.who.int)

• WHO declares BDBV PHEIC on 17 May 2026; no licensed vaccines for BDBV.
• Ervebo (rVSV-EBOV-GP) licensed only for Ebola virus (EBOV).
• Review of animal studies shows survival benefit in one study (75% vs 25% control) but small sample sizes and inconsistent results; human antibody data show limited cross-reactivity.
• WHO recommends against programmatic use of Ervebo for BDBV due to insufficient evidence and risk of false security.
• Accelerated R&D for BDBV-specific vaccines and pan-Orthoebolavirus vaccines prioritized; ethical trials needed.

"WHO has determined that the licensed Ebola vaccine Ervebo, which targets the Zaire ebolavirus species, should not be used outside controlled research settings against the current Bundibugyo virus (BDBV) outbreak, declared a PHEIC on 17 May 2026. Evidence reviewed from two nonhuman primate studies and one human antibody study showed limited and inconclusive cross-protection. Ervebo is licensed only for EBOV. WHO recommends accelerated development of BDBV-specific and pan-Orthoebolavirus vaccines. Proven public health measures (surveillance, contact tracing, safe burials, community engagement) remain paramount. National authorities may consider Ervebo in research protocols, prioritizing ethical standards."