Inside the high-stakes race to develop an Ebola vaccine for an escalating outbreak

What the report says

Nature reported that the University of Oxford has begun a phase I clinical trial of a vaccine candidate against Bundibugyo ebolavirus, with the first volunteer vaccinated four days before publication. The start came 68 days after the World Health Organization declared the Ebola outbreak in the Democratic Republic of the Congo and Uganda a public-health emergency of international concern. Nature cited official figures showing 3,200 confirmed cases and 1,405 deaths in the DRC by 27 July.

The vaccine, known as ChAdOx1, is being developed by the Oxford Vaccine Group and uses the same viral-vector platform as the Oxford–AstraZeneca COVID-19 shot, modified to carry instructions for a Bundibugyo ebolavirus protein. Teresa Lambe, Oxford’s head of vaccine immunology and lead scientific investigator for the study, told Nature that prior work on Ebola and other filoviruses, existing genetic material and parallel work on manufacturing, non-clinical studies and regulatory preparation helped the team move quickly. About 620,000 doses have already been produced, according to the report.

The initial UK trial is expected to enroll about 50 adults aged 18 to 55 and will examine safety, signs of inflammation and immune responses. If the early data support it, Oxford aims to work with the MRC Uganda Virus Research Institute on further studies, with larger trials in outbreak settings in Uganda targeted later in 2026.

Nature also reported that two other vaccine candidates are in development: an mRNA vaccine from Moderna expected to enter clinical trials next month, and a candidate from the International AIDS Vaccine Initiative similar to the WHO-recommended vaccine for Zaire ebolavirus. All three efforts are funded by the Coalition for Epidemic Preparedness Innovations.