Global Health Groups Rush to Develop Bundibugyo Ebola Vaccines

Race Against a Rare Strain

An unusual Ebola outbreak spreading across Central Africa has exposed a critical gap in global health preparedness. The Democratic Republic of the Congo and Uganda are battling a growing epidemic of Bundibugyo ebolavirus, with around 500 suspected cases and more than 130 deaths reported . The World Health Organization declared the situation a public health emergency of international concern on May 17, 2026 .

Unlike the more familiar Zaire strain that devastated West Africa in 2014-2016, Bundibugyo has no approved vaccines or specific treatments . This strain kills 30% to 40% of infected people, making it less lethal than Zaire which can cause death in up to 90% , but its rarity has left the world unprepared for this moment.

Bundibugyo virus has caused relatively few outbreaks historically and has remained a lower research priority compared with the more lethal Zaire strain . Only two previous epidemics, in 2007 and 2012, have been recorded , explaining why vaccine development lagged behind.

Emergency Vaccine Development

Global health organizations are now scrambling to bridge this gap. The Coalition for Epidemic Preparedness Innovations (CEPI) announced it will urgently accelerate development of three investigational vaccines targeting Bundibugyo ebolavirus, with no licensed vaccines available and none in clinical development .

CEPI is providing three entities with roughly $62 million in funding to help manufacture and test Bundibugyo vaccines . These include candidates developed by IAVI; Moderna; and the University of Oxford, which will be manufactured at the Serum Institute of India . CEPI committed $50 million to a vaccine candidate being developed by Moderna which uses the mRNA technology pioneered in its Covid vaccine .

The most promising candidate uses proven technology. One candidate uses the rVSV vaccine platform upon which an approved and WHO-prequalified vaccine against Zaire ebolavirus is based . Research from 2013 demonstrated this vaccine provided very strong protection against Bundibugyo in monkeys , but the vaccine "just sat there" for more than a decade because of a lack of interest, particularly from pharmaceutical firms .

Timeline Challenges

Even with emergency funding, help may come too late for the current outbreak. The WHO estimated it would take seven to nine months before the rVSV vaccine is ready to be tested in humans . The rVSV-BDBV-GP candidate is expected to be the most effective single-dose option but may not be available for evaluation in the current outbreak, and no Bundibugyo-specific vaccine is expected to be available for near-term outbreak deployment .

Another candidate vaccine, ChAdOx1 Bundibugyo being developed by Oxford University/Serum Institute of India, could potentially become available within 2–3 months for efficacy assessment through a clinical trial . This may be the first clinical-grade product to become available, with a two-dose regimen believed necessary for optimal protection .

Meanwhile, existing tools offer limited help. There are currently two approved vaccines against Ebola disease, but neither is approved for use in cases of infection with the Bundibugyo virus . The licensed Ervebo vaccine is indicated for Zaire ebolavirus only, with limited evidence on cross-protection, and WHO does not recommend it for use outside of controlled research settings .

Lessons for Future Preparedness

This outbreak highlights how neglected diseases can suddenly demand urgent attention. Most Ebola countermeasure development has focused on Ebola Zaire, which was traditionally the more deadly and common strain, meaning other Ebola strains have not had that same level of vaccine development . The scientific community is now paying the price for this narrow focus.

Even if vaccines do not reach affected communities before this outbreak is brought under control, investing in Bundibugyo research and development now is an investment in protecting the communities and generations who will face future outbreaks . CEPI and its development partners are committed to enabling rapid, affordable supply of Bundibugyo virus vaccines to affected countries and to the populations that need them .

The current crisis serves as a stark reminder that pandemic preparedness requires investing in vaccines for all potential threats, not just the most visible ones. While researchers race to develop tools for this outbreak, the real test will be whether the global health community maintains this urgency for rare pathogens when headlines fade.