The World Health Organization (WHO) has recommended the addition of two new candidate vaccines to an ongoing clinical trial in the Democratic Republic of the Congo (DRC) as researchers intensify efforts to combat the Bundibugyo Ebola outbreak.
The vaccines, ChAdOx1, developed by the University of Oxford in partnership with the Serum Institute of India, and Moderna’s mRNA-1469, are designed to protect against the Bundibugyo virus responsible for the current outbreak.
According to a WHO statement released on Wednesday, November 4, the organisation’s independent Technical Advisory Group on Candidate Vaccines Prioritization recommended both candidates for further clinical evaluation based on available preclinical and early clinical evidence.
The vaccines will be introduced into the ongoing Tumaini clinical trial once national approvals are secured.
The recommendation marks the first time vaccines specifically developed against the Bundibugyo virus will be evaluated during an outbreak of the disease.
WHO Director-General Dr Tedros Adhanom Ghebreyesus said the progress demonstrated the importance of scientific research and international partnerships in responding to disease outbreaks.
He noted that while vaccines alone would not end the outbreak, they could provide an additional tool to help bring it under control.
The Tumaini trial, led by the DRC’s National Institute of Biomedical Research, uses a ring-vaccination approach that targets contacts of people confirmed to have Bundibugyo virus disease.
Four vaccination rings have already been established, with additional ones being prepared. The trial initially included Ervebo, a vaccine previously proven effective against the Zaire ebolavirus, which is a different species from the Bundibugyo virus.
Meanwhile, research into potential treatments is also progressing through the WHO-sponsored PARTNERS trial, launched in July.
The study is evaluating whether the monoclonal antibody MBP134, the antiviral drug remdesivir or a combination of both can improve survival among patients with confirmed Bundibugyo virus disease.
Another treatment candidate, maftivimab, is also expected to be added to the trial, while a separate study is assessing obeldevisir as a potential post-exposure preventive treatment.
WHO said initial findings from the treatment studies are expected in the coming months, while results from the vaccine trial are anticipated in early 2027.
The research is being conducted with support from international health institutions and partners, including the Africa Centres for Disease Control and Prevention, Médecins Sans Frontières, the University of Antwerp and the Coalition for Epidemic Preparedness Innovations.
