The fight against a deadly Ebola strain has taken another step forward, with the World Health Organization (WHO) recommending two additional vaccine candidates for clinical evaluation in the Democratic Republic of the Congo (DRC).
The candidates, ChAdOx1, developed by the University of Oxford in partnership with the Serum Institute of India, and Moderna’s mRNA-1469, were developed specifically to target the Bundibugyo virus responsible for the ongoing outbreak.
According to a WHO announcement on November 4, 2026, the recommendation followed a review of available early clinical and preclinical evidence by its independent Technical Advisory Group on Candidate Vaccine Prioritization.
The two candidates are expected to join the ongoing Tumaini clinical trial following national approvals. The trial, led by the DRC’s National Institute for Biomedical Research, uses a ring-vaccination approach that involves vaccinating contacts of people with confirmed Bundibugyo virus disease.
The development is significant because there is currently no licensed vaccine specifically approved to prevent infection with the Bundibugyo virus.
Although Ervebo is an approved Ebola vaccine, its established protection is against the Ebola virus species, not Bundibugyo. Its effectiveness against the latter is still being investigated.
WHO said four vaccination rings have already been established, with additional groups being prepared. Results from the vaccine trial are expected in early 2027. The organisation, however, stressed that vaccines alone will not end the outbreak, highlighting the importance of early treatment, contact tracing, isolation and community engagement.
The development offers another opportunity to strengthen the response to one of the most challenging Ebola outbreaks in recent years.
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