The United States is stepping into a more direct role in the Ebola response in the Democratic Republic of Congo by supplying doses of an experimental antibody drug for use in clinical trials, a notable shift from its earlier position that limited access to Americans at high risk of exposure.
The decision centers on MBP134, an investigational monoclonal antibody therapy developed by Mapp Biopharmaceutical, and comes as health authorities warn the current outbreak could escalate further without rapid, coordinated intervention. The U.S. Department of Health and Human Services said the doses will be deployed under compassionate use in Congo and simultaneously used to generate clinical trial data that could support future regulatory approval.
Officials declined to disclose the number of doses being shipped. The move marks the first time Washington has indicated it will directly support outbreak-based clinical trials of the treatment using stockpiled supplies, rather than reserving them exclusively for U.S. nationals. The policy change follows years of tension between domestic biosecurity priorities and global outbreak response demands.
The widening outbreak, driven by the Bundibugyo strain of Ebola, has already become one of the largest on record. Government figures report 1,094 confirmed cases and 277 deaths in Congo, with additional infections and fatalities reported in neighboring Uganda. Health experts warn the true scale may be higher in remote or insecure areas where surveillance is limited.
Unlike the Zaire strain that has driven most recent Ebola epidemics, Bundibugyo currently has no approved vaccine or targeted therapy, increasing pressure on experimental treatments now entering field trials.
The World Health Organization said shipments of MBP134 and other investigational therapies are already reaching affected areas. WHO is coordinating trial logistics with local governments and partner institutions, including preparations for patient enrollment in treatment centers across Congo and Uganda.
Clinical trials are expected to begin in the coming weeks and will test MBP134 both as a standalone therapy and in combination with antiviral drugs. One of those candidates is remdesivir, known commercially as Veklury, developed by Gilead Sciences and widely used during the COVID-19 pandemic. Another, obeldesivir, is being evaluated as a preventive option for individuals exposed to the virus.
The MBP134 trial is sponsored by the WHO and led by researchers at the University of Oxford, working alongside Congolese and Ugandan health authorities. Parallel trials of other antivirals are being coordinated by African and international partners, including the Africa Centres for Disease Control and Prevention and European research agencies.
Regulators and ethics committees in Congo and Uganda are currently reviewing trial protocols. While earlier studies have indicated the drugs are generally safe, none have demonstrated efficacy against the Bundibugyo strain, leaving their real-world impact uncertain.
Vaccine development is moving on a slower timeline. Early-stage candidates supported by groups such as the Coalition for Epidemic Preparedness Innovations, or CEPI, include platforms developed by Oxford and the Serum Institute of India, as well as mRNA-based vaccines from Moderna. Officials say Phase 1 trials could begin in the coming months in countries outside the outbreak zone, including the United Kingdom and potentially Uganda.
CEPI leadership has said the infrastructure for early trials is largely in place, but later-stage studies and deployment strategies remain unresolved.
Despite the urgency, global health officials stress that all experimental interventions must still pass through controlled trials before widespread use, even as pressure builds to accelerate access in affected communities.
On the ground, containment efforts face significant obstacles. The outbreak is concentrated in parts of eastern Congo where insecurity, weak health systems and mistrust of authorities complicate surveillance and treatment.
One of the hardest-hit areas is Mongbwalu in Ituri province, a gold-rich mining hub where artisanal extraction continues despite the risk of infection. The mobility of workers in and out of mining sites has made contact tracing more difficult, while dense working conditions increase transmission risk.
Health workers describe a setting where economic necessity often outweighs fear of disease. Many miners say they continue working because stopping would mean losing their only source of income, even as they acknowledge the risk of infection through close contact in crowded pits and processing areas.
The outbreak has already reached 17 provinces since it was first declared in May after unexplained deaths in Mongbwalu. It is now classified as the third-largest Ebola outbreak in recorded history.
Aid agencies warn that mistrust of medical systems, combined with reliance on traditional healers in some communities, continues to slow early detection and treatment. Safe burial teams and contact tracers operate under difficult conditions, often in areas affected by long-standing armed group activity.