Closing the gap: The race for a Bundibugyo Ebola vaccine

Why is there a medical need The outbreak that began in mid-May 2026 in the Democratic Republic of the Congo (DRC), with cross-border spread to Uganda, is caused by Bundibugyo ebolavirus (BDBV) — a species distinct from the Zaire ebolavirus (EBOV), the only ebolavirus currently targeted by a licensed vaccine. WHO declared the epidemic a Public Health Emergency of International Concern (PHEIC) on 18 May 2026, and Africa CDC declared a Public Health Emergency of Continental Security (PHECS) in the same period (Gavi, 21 May 2026). By early June, WHO and Africa CDC had already launched a joint continental Ebola preparedness and response plan seeking US$518 million to support African countries’ detection and response capacity (WHO Disease Outbreak News, 8 June 2026). The core problem is not one of access or supply, but of immunology. Neither of the two licensed products, Ervebo (Merck’s rVSV-ZEBOV) nor Zabdeno/Mvabea (Janssen’s Ad26.ZEBOV/MVA-BN-Filo), was designed against BDBV....