Why the Congo Ebola Outbreak Is So Hard to Stop

On August 18, 2026, the World Health Organization warned that the Ebola outbreak in the Democratic Republic of the Congo is still a global health emergency. Confirmed infections have surpassed 5,000 and the death toll has exceeded 2,320 (Al Jazeera). WHO Director-General Tedros Adhanom Ghebreyesus said the outbreak is spreading faster than any before and is far from under control.

This is the seventeenth Ebola outbreak recorded in the DRC and its deadliest, surpassing fatalities from the 2018–2020 outbreak. The virus behind it is called the Bundibugyo ebolavirus species. There is no approved vaccine or treatment for it. That matters because earlier Ebola outbreaks in the region were caused by a different species called Zaire ebolavirus, and for that one, a vaccine was available under compassionate-use protocols — meaning it was given to people before full approval because the situation was urgent.

The outbreak was officially declared on May 17, 2026. That same day, WHO determined that the epidemic in the DRC and Uganda constituted a Public Health Emergency of International Concern, or PHEIC — its highest-level alert, meant to trigger a coordinated global response (WHO). Genetic sequencing, however, indicates that the virus was already spreading from person to person as early as February 2026, roughly three months before anyone formally declared an outbreak. The IHR Emergency Committee, a panel of experts that advises WHO under international health rules, held its first meeting on the epidemic on May 22, 2026, and issued temporary recommendations to member states.

The numbers have climbed quickly. As of July 2, 2026, WHO reported 1,406 cases with an average of 38 new confirmed cases per day (WHO). By August 18, that figure had passed 5,000 — more than three times higher in roughly seven weeks.

Two things make the response especially difficult. First, the eastern DRC is dangerous for aid workers. Since the emergency was declared on May 17, WHO has documented 12 attacks on health care in the outbreak zone (WHO). On August 17, 2026, WHO published guidance on protecting health workers and keeping essential health services running during the response (WHO).

Second, with no licensed vaccine for the Bundibugyo virus, responders are turning to experimental candidates that are still being tested. The first volunteer received an experimental Bundibugyo-strain vaccine in the United Kingdom in July 2026. Hundreds of thousands of doses of an Oxford University-developed candidate have been manufactured in India as of August 2026, but no results from large-scale trials confirming whether it actually works have been reported yet. This creates a hard choice: give people an unproven vaccine during a fast-moving emergency, or wait for evidence while the virus keeps spreading.

WHO has adapted to the region's rough terrain by recruiting motorbike riders as surveillance and response officers, using their travel routes to track down people who may have been exposed to the virus and to report new alerts. The outbreak crosses borders, with confirmed cases in both the DRC and Uganda, which adds complexity to coordinating the response.

The broader context here is how the virus itself, a fragile health system, and ongoing conflict all work against each other. The Bundibugyo species was first identified in 2007 in Uganda's Bundibugyo District. It has historically killed a smaller share of infected people than the Zaire species, but its spread patterns are harder to predict. Think of Ebola containment like fighting a fire: you isolate the sick (remove fuel), trace their contacts (find every spark), vaccinate in a ring around cases (build a firebreak), and ensure safe burials (eliminate hidden embers). In eastern DRC, every one of those steps is under strain because of armed groups, poor roads, and the lack of a licensed vaccine. The share of infected people who have died — about 46% based on the August 18 figures — is within the range seen in earlier Bundibugyo outbreaks, but the total number of deaths is the highest ever recorded for this species.

What to watch next is whether the Oxford vaccine candidate moves through testing fast enough to win emergency approval, and whether the 12 attacks on health care since the emergency was declared are getting worse or staying at the same level. The speed Tedros describes leaves little room for either of those things to go the wrong way.