Human trials have officially begun as an escalating Ebola outbreak driven by the Bundibugyo virus spreads across Central Africa. According to Nature.com, the first volunteer was vaccinated with the experimental ChAdOx1
vaccine just 68 days after the World Health Organization declared the current epidemic a public-health emergency of international concern.
Oxford University Begins Human Trials for ChAdOx1 Ebola Vaccine
The vaccine is being evaluated in a phase I clinical trial conducted by the Oxford Vaccine Group at the University of Oxford in the UK. Teresa Lambe, head of vaccine immunology at Oxford, serves as the lead scientific investigator for the study. The candidate utilizes the same vector platform as the Oxford–AstraZeneca COVID-19 vaccine while carrying genetic instructions specifically targeting the Bundibugyo ebolavirus protein.
Scale and Severity of the Central Africa Outbreak
The epidemic has severely impacted the Democratic Republic of the Congo (DRC) and Uganda, with confirmed cases also reaching Uganda’s capital of Kampala. Data from the Centers for Disease Control and Prevention indicates that officials confirmed 3,200 cases and 1,405 deaths in the DRC alone by July 27.
This event marks the 17th Ebola outbreak in the DRC. The virus has been confirmed across Haut-Uele, Ituri, Nord-Kivu, Sud-Kivu, and Tshopo provinces. Federal health officials report that this epidemic is spreading substantially faster than previous historical outbreaks, crossing 1,000 confirmed cases within just 40 days of response activation. By comparison, the 2018 outbreak in North Kivu required approximately 235 days to reach that same threshold. The rapid transmission rate has pushed the crisis to become the third largest Ebola outbreak on record.
Global Response and Additional Vaccine Candidates
The Coalition for Epidemic Preparedness Innovations (CEPI) is funding all three primary vaccine candidates currently in development. Alongside the Oxford trial, Bloomberg.com reported that CEPI is financing production for a separate experimental clinical-trial batch of the Bundibugyo vaccine with Merck & Co., targeting manufacturing by the end of the year and subsequent human studies. Furthermore, Moderna is developing an mRNA vaccine in Cambridge, Massachusetts, expected to enter clinical trials soon, while the International AIDS Vaccine Initiative is advancing a similar candidate.
Efforts by responders have faced steep operational hurdles. Semafor noted that health workers attempting to contain the Bundibugyo strain have been hindered by shortages of medical equipment, widespread misinformation, and community distrust. The head of CEPI described the ground situation plainly, stating that the epidemic is fast becoming a humanitarian crisis.
Current Trial Parameters and Next Phases
The ongoing Oxford phase I trial aims to recruit approximately 50 healthy adults aged 18 to 55 in the United Kingdom. Researchers are monitoring participants for baseline safety, physical signs of inflammation, and immune responses.
Following data evaluation from the initial UK cohort, researchers plan to expand testing to partner institutions, including the MRC Uganda Virus Research Institute, involving healthy volunteers in the region. Investigators are working concurrently on non-clinical data, manufacturing frameworks, and clinical protocols to enable subsequent phase II and III trials in active outbreak scenarios as quickly as possible.
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