WHO emergency guidance on the use of licensed Ebola vaccine during Bundibugyo virus disease outbreaks: interim guidance, 31 August 2026

This updated WHO emergency guidance provides recommendations on the potential use of Ervebo®, the only licensed Ebola vaccine, during outbreaks caused by Bundibugyo virus (BDBV), taking into account the evolving outbreak in the Democratic Republic of the Congo and additional animal, immunological and observational evidence reviewed by the Strategic Advisory Group of Experts on Immunization (SAGE) in August 2026. Although some findings suggest possible cross-protection against BDBV, the available evidence remains insufficient to determine whether Ervebo® provides clinically meaningful protection or to quantify vaccine efficacy in humans.

The guidance outlines the benefits, risks and uncertainties associated with off-label use of Ervebo® and recommends that the vaccine be used only within research protocols. It emphasizes the importance of rapidly generating robust efficacy data through a ring randomized controlled trial, maintaining proven outbreak-control measures, clearly communicating the unknown efficacy against BDBV, and accelerating the development and evaluation of BDBV-specific vaccines and other countermeasures to inform future policy.

Auteurs