The United States has started releasing doses of an experimental Ebola treatment to support urgent clinical trials in the Democratic Republic of Congo, as health teams race to contain a growing outbreak that has already crossed borders and stretched response efforts in Central Africa.
The move involves an antibody-based drug developed by Mapp Biopharmaceutical, which will now be used both under compassionate access and within structured clinical studies in affected regions.
As reported by Reuters, a spokesperson from the U.S. Department of Health and Human Services said the exact number of doses being provided has not been disclosed.
The spokesperson said the step is aimed at strengthening scientific evaluation during the outbreak and could guide future approval decisions.
“The trial data could help inform future regulatory review and potential U.S. approval, the spokesperson said.”
The World Health Organization confirmed that shipments of the experimental treatment, alongside other candidate therapies, are already being sent as preparations for trials advance in Congo and nearby countries. Health teams are working to enrol patients at selected treatment centres under coordinated study plans.
The outbreak, linked to the Bundibugyo strain of Ebola virus disease, has recorded more than 1,000 infections and over 250 deaths. Small numbers of cases have also been reported in Uganda, raising concerns about regional spread.
Officials said this is the first time the United States government has directly supported the use of stockpiled doses for clinical testing of the Mapp antibody treatment. Earlier access had mainly been limited to Americans considered at high risk of exposure.
Washington has already committed hundreds of millions of dollars to the response and is also building a quarantine facility in Kenya for American citizens, as part of wider efforts to prevent the virus from reaching the United States.
Health agencies say the Mapp treatment is expected to be among the first therapies tested in the current outbreak, which was declared a public health emergency by the World Health Organization just weeks ago and is now among the largest Ebola outbreaks recorded.
Despite the urgency, global health authorities have stressed that all experimental medicines must still go through controlled clinical trials before wider use is considered.
Trials involving the Mapp antibody therapy and two antiviral drugs developed by Gilead Sciences are expected to begin in the coming weeks, according to researchers and officials involved in the response.
The Mapp drug will be tested both on its own and in combination with remdesivir, a drug widely used during the COVID-19 pandemic.
The trial programme is being coordinated under the World Health Organization, with implementation led by the University of Oxford together with health authorities in Congo and Uganda.
Another antiviral drug, obeldesivir, will also be tested as a preventive option, with early-stage trials expected to begin this month. The study will be led by authorities in Congo and Uganda, alongside regional health bodies and international research partners.
Gilead Sciences said it has not released detailed shipment information but confirmed it is supporting requests for both investigational drugs.
Regulatory and ethics committees in Congo and Uganda are currently reviewing trial protocols ahead of patient enrolment.
While treatment trials are moving forward, vaccine development remains at an earlier stage. The World Health Organization says vaccine candidates require more time for manufacturing and safety testing before use in outbreak areas.
Early vaccine trials could begin as soon as July, likely in the United Kingdom and possibly Uganda, according to officials leading global preparedness efforts.
Several vaccine candidates are being supported internationally, including ones developed using traditional platforms and newer mRNA technology.
Officials involved in the planning say resources are available, but decisions on where and how early trials will take place are still being finalised.
Health experts warn that carrying out trials in conflict-affected and insecure areas remains difficult due to mistrust, attacks on health workers, and disrupted logistics. They say building community trust and ensuring access to successful treatments after trials will be critical.