The Ebola outbreak in central Africa is spreading rapidly, the World Health Organization said, complicating efforts to contain a rare virus strain for which no approved treatment or vaccine exists.
The agency upgraded its risk assessment to “very high” in the Democratic Republic of Congo, where there are now almost 750 suspected cases and 177 deaths from the disease. Two cases, including one death, were also confirmed in neighboring Uganda after they traveled from the DRC.
The outbreak is caused by the rare Bundibugyo strain. There is no specific vaccine, and the mortality rate is as high as 50 per cent. It appears to have circulated through eastern Congo’s Ituri province, a conflict-hit mining region, for about two months before authorities recognized what they were dealing with.
The outbreak is “especially challenging,” WHO Director-General Tedros Adhanom Ghebreyesus told reporters Friday, citing the fighting, displacement of people and the transient population of miners. “There is significant distrust of outside authorities among the local population.”
Tedros this month took the unprecedented step of declaring a global public health emergency before convening the WHO’s emergency committee, due to the speed and scale of the outbreak.
Governments across the world are tightening border screening and quarantine preparedness as health authorities work to contain the outbreak. An India-Africa summit due to begin in New Delhi at the end of May was postponed indefinitely.
Uganda has effectively closed its border with the DRC, suspending flights to and from the country as well as all public transport except those moving goods and food. It also stopped weekly bazaars in high-risk regions where communities often cross the porous border to trade and shop for essentials.
In the DRC, contract-tracing has expanded to 1,400 people, said Anne Ancia, the WHO’s representative in the country. Case numbers are expected to rise, she added, reflecting the outbreak response becoming more established.
“We are running behind, we are not yet under control,” she said.
Africa Centres for Disease Control and Prevention Director General Jean Kaseya said in an interview that pledged funding isn’t reaching the front-line health workers.
“Where is this money?” he asked, citing a lack of personal, protective equipment, medicines and treatment centers. “Why is this money is not in the field?”
Treatments
The agency is looking at running clinical trials for potential treatments as part of the response. WHO advisers prioritized two antibody therapies made by Regeneron Pharmaceuticals Inc. and Mapp Biopharmaceutical Inc.
The WHO is also considering trials for two antivirals made by Gilead Sciences Inc., obeldesivir and remdesivir, as post-exposure treatment for high-risk contacts. The timing depends on governments in affected countries.
A WHO technical advisory group met Tuesday to discuss which potential vaccines should be prioritized. Two vaccines for Ebola were developed during a years-long outbreak in West Africa a decade ago, one from Merck & Co. and another from Johnson & Johnson. However, both were designed to block the more common and deadly Zaire strain of the virus.
The agency is reviewing potential vaccine candidates, though no full prioritization has been completed, said Sylvie Briand, the WHO’s chief scientist. Merck’s Ervebo vaccine developed for the Zaire strain has not been recommended as a primary choice due to “very little evidence” it provides cross-protection against the Bundibugyo strain, she said.
Briand said a more promising candidate is an rVSV vaccine similar to the Ervebo shot, but designed for the Bundibugyo strain. However, no doses are currently available for clinical trials, and it could take six to nine months to prepare supplies if development is prioritized.
Bundibugyo virus was first identified in Uganda in 2007 after health officials struggled for five months to understand why patients with Ebola-like symptoms were testing negative for known strains.
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Published on May 23, 2026