Bundibugyo ebolavirus
Rare Ebola species with no licensed vaccine or treatment, now causing its largest recorded outbreak.
On 20 August, 20,000 of 70,000 Ervebo doses released to DR Congo were set aside for a Bundibugyo ebolavirus Phase 3 trial, testing whether a Zaire-targeted vaccine can protect against this species.
Last refreshed: 22 September 2026 · Appears in 1 active topic
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Timeline for Bundibugyo ebolavirus
Killed 59.7% of confirmed patients in North Kivu
Pandemics and Biosecurity: Ebola shifts south to DR Congo's ButemboRemained without a licensed vaccine
Pandemics and Biosecurity: WHO: 2,000 Congolese workers get ErveboBecame the target of CEPI's fifth candidate
Pandemics and Biosecurity: CEPI awards Minapharm US$16.5m for EbolaMentioned in: WHO calls Uganda's Ebola outbreak over
Pandemics and BiosecurityMentioned in: 70,000 Ervebo doses, 20,000 as a trial
Pandemics and BiosecurityBackground
Bundibugyo ebolavirus is an Ebola species first identified during Uganda's 2007 outbreak, which recorded 131 cases. Its small historic record made the absence of species-specific clinical evidence a lasting problem before the 2026 emergency.
No licensed vaccine, monoclonal antibody therapy or antiviral was available for Bundibugyo ebolavirus in May 2026. Ervebo, Inmazeb and Ebanga target Zaire ebolavirus instead. That distinction matters because evidence from one Ebola species cannot establish protection or treatment benefit for another. Bundibugyo therefore remains important as a test of whether outbreak medicine can respond before a rare pathogen becomes a large emergency.
Vaccine evidence enters human trials
On 20 August, DR Congo received 70,000 Ervebo doses, with 20,000 allocated to a Phase 3 trial against Bundibugyo ebolavirus. The allocation turns a vaccine designed for Zaire ebolavirus into an emergency intervention and a test of whether cross-species protection exists.
On 3 August, a volunteer received the first dose of Moderna's Bundibugyo-matched mRNA-1469 candidate in an 80-person Phase 1 trial. On 31 July, Hilleman Laboratories also began trial production of an rVSV candidate matched to the species. Neither step established protection in people by 20 August, but both address the absence of a licensed matched vaccine.
The outbreak sets a national record
On 12 August, the World Health Organization counted 4,665 Bundibugyo Ebola cases in DR Congo, passing the country's previous 3,317-case Ebola record from 2018 to 2020. The count placed this species at the centre of the largest Ebola emergency DR Congo has recorded.
On 20 July, WHO said that more than 80% of new cases were appearing outside known contact chains. For Bundibugyo ebolavirus, that meant the outbreak was no longer defined only by its rarity or its historical case record: surveillance failures were allowing transmission to outrun the response.
The outbreak sets a national record
Has the Bundibugyo Ebola outbreak been contained in Uganda?
What is the largest Ebola outbreak ever recorded?
How does the 2026 Bundibugyo Ebola outbreak's death rate compare with past outbreaks?
How does the 2026 Ituri Bundibugyo outbreak compare to previous outbreaks?
Why has Ebola spread to France from the DRC outbreak?
Is there a vaccine being developed for Bundibugyo Ebola?
Reference
When was Bundibugyo ebolavirus first discovered?
Why has there never been an Ebola treatment for the Bundibugyo strain?
Recently resolved
Is there a vaccine or treatment for Bundibugyo Ebola?
Where has the current Bundibugyo Ebola outbreak spread outside Africa?
Why is the Bundibugyo Ebola outbreak still not under control despite funding?
How deadly is Bundibugyo Ebola compared to the Zaire strain?
Why can't doctors use existing Ebola drugs to treat the current outbreak?
