WHO launches Ebola vaccine trial in DRC as outbreak worsens

The trial, named Tumaini — meaning 'hope' in Swahili — began in the DRC's outbreak epicentre on 23 October 2026
Scientists are testing whether an already-approved Ebola vaccine can protect against a strain it was never designed to fight
Two additional vaccine candidates, including an mRNA jab from Moderna, are set to be brought into the trial as it expands

A post. — A medical practitioner giving a man an injection. Images: Luke Dray / Stringer/Getty
Source: Getty Images

The World Health Organisation has kicked off a landmark clinical trial in the Democratic Republic of the Congo to find a vaccine capable of fighting the Bundibugyo strain of the Ebola virus, for which no approved vaccine currently exists.

According to reports, named Tumaini, the Swahili word for "hope", the trial began on Friday, 23 October 2026, in Bunia, capital of the northeastern Ituri province and the current epicentre of an outbreak that has already claimed more than 4,600 lives from over 9,700 recorded cases, making it the deadliest Ebola outbreak in the DRC's history.

The trial opened with the administration of the first dose of Ervebo, a vaccine already approved and proven highly effective against the more common Zaire strain of Ebola. Researchers are now studying whether Ervebo also offers cross-protection against the Bundibugyo strain, a question that has never been answered under clinical conditions.

The Tumaini trial is built on an adaptive framework, meaning it can be expanded to include additional candidates as the science develops. Two specialised vaccines are being prepared for inclusion: an adenovirus-vector vaccine developed by the University of Oxford and an mRNA vaccine from Moderna, both of which are currently in early-stage testing.

To ensure the trial reaches those at greatest risk, researchers are employing a ring vaccination strategy, targeting people who have had direct contact with confirmed cases. Healthcare workers, pregnant women, and children aged 12 and older are among the priority groups.

WHO Director-General Tedros Adhanom Ghebreyesus also confirmed that efforts to reduce the outbreak's mortality rate will not rely on vaccines alone. Clinical trials for two treatments, the monoclonal antibody MBP134 and the antiviral drug remdesivir, are scheduled to begin in Ituri province the following week.

WHO launches Ebola vaccine trial in DRC as outbreak worsens

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