The director-general of the World Health Organization conveyed cautious optimism about the current Ebola outbreak in the Democratic Republic of the Congo (DRC), saying disease transmission rates are declining in most of the affected provinces. He emphasized that, despite encouraging trends in several areas, the epidemic "continues to grow and continues to kill," and that substantial work remains over the coming months to bring the outbreak under control.
WHO noted a notable reduction in cases in Ituri province — described as the epicenter of the epidemic — but underscored that the decline is from a previously very high level of transmission.
The outbreak is caused by the Bundibugyo species of Ebola. As of the reporting date, there were 7,258 confirmed cases and 3,510 deaths across seven provinces in northeastern DRC. That tally makes this the second-largest Ebola outbreak on record.
By comparison, the West African epidemic of 2014–2016 was larger and ran for about two years. In the present DRC event, formal detection of the outbreak occurred in mid-May, although subsequent investigations suggest the virus may have been circulating earlier in the year.
Response operations have been hampered by long-running insecurity in the affected region. Decades of violence have produced large numbers of displaced people, disrupted livelihoods, and left many struggling to feed their families. Those structural and security challenges complicate case finding, contact tracing, safe patient care, and vaccination efforts.
Health officials have also observed that in some communities Ebola has been perceived as a lower-priority threat compared with persistent risks such as malaria, food insecurity, and political violence. This view affected early cooperation with responders and uptake of control measures.
WHO leadership reported that rising Ebola deaths as the outbreak expanded have altered local perceptions to some degree. Local leaders and communities have started to recognize the seriousness of the epidemic, and officials described improved cooperation with response teams compared with earlier in the outbreak.
Nevertheless, the WHO director-general warned that pockets of risk and operational barriers remain, and that continued engagement with communities will be required to sustain and extend recent gains.
WHO announced plans for a Phase 3 randomized clinical trial of Ebola vaccines to begin in the coming weeks. The first vaccine planned for deployment in that trial is Merck’s Ervebo, which targets the Zaire Ebola virus. WHO officials said there is some evidence Ervebo may offer cross-protection against the Bundibugyo species, and that vaccines specifically developed for Bundibugyo will be incorporated into the Phase 3 trial once they complete Phase 1 safety and dosing evaluations.
Separately and independently of the randomized trial, frontline workers in hot spots will be offered vaccination as part of an observational study expected to start imminently. That study, being conducted by DRC authorities and Doctors Without Borders (Médecins Sans Frontières), will give participants a dose of Ervebo followed one month later by a dose of an experimental vaccine designed to protect against the Sudan species of Ebola. The observational design will compare case rates among vaccinated individuals versus people who are not vaccinated.
WHO’s department of science for health indicated that the Phase 3 trial will evolve as additional candidate vaccines complete early-phase testing, enabling a broader assessment of vaccine options against the currently circulating species.
While transmission appears to be decreasing in many affected provinces and community cooperation has improved, WHO leadership stressed that the epidemic still causes deaths and that control is not yet achieved. The agency warned that response teams face months of work ahead and that vigilance, sustained operations, and expanded vaccination efforts will be required to stop the outbreak.
Operational challenges tied to insecurity, displacement, and competing health and survival priorities in affected communities will remain major obstacles. WHO and partners plan to continue combining surveillance, clinical care, community engagement, and vaccine studies to reduce transmission and prevent further deaths.