The World Health Organization has begun enrolling patients in a clinical trial of two experimental Ebola treatments in the Democratic Republic of the Congo, as the death toll from the Bundibugyo strain outbreak passed 500. Congolese health ministry data released on 5 July recorded 1,561 confirmed cases and 506 deaths, a case fatality rate of 32.4 per cent. The trial, launched at the CME Ebola treatment centre in Rwampara, Ituri province, marks the first systematic evaluation of therapeutics against this rare viral strain, for which no approved vaccine or specific treatment exists.

The trial is designed as an adaptive platform study, allowing researchers to add or drop treatment arms as evidence emerges and to pause and resume enrolment across future outbreaks. Patients are being randomised to receive a single infusion of the monoclonal antibody cocktail MBP134, a daily course of the antiviral remdesivir for up to ten days, both therapies combined, or optimised supportive care alone. The primary endpoint is all-cause mortality at 28 days. The protocol deliberately includes children, pregnant women and lactating women, groups historically excluded from outbreak research. MBP134 has shown broad activity against multiple Ebola species in laboratory and animal studies but has limited human experience; remdesivir has extensive safety data from COVID-19 but uncertain benefit against Ebola. The University of Oxford serves as the central coordinating hub, with the WHO sponsoring the study.

The outbreak, declared on 15 May in Ituri and since spread to North Kivu and South Kivu provinces, is the largest ever recorded for the Bundibugyo strain. It has also crossed into Uganda, where 20 confirmed cases include 15 imported from Congo and two deaths. France confirmed a first positive case in a doctor returning from a mission in the affected zone. Congolese authorities have banned mass gatherings in the capital Kinshasa and three other provinces to curb transmission. Contact tracing has reached 81.6 per cent, but containment is complicated by armed conflict and community resistance: health workers and facilities have been attacked, and treatment centres in Ituri are struggling to meet demand even as daily confirmed cases have declined in recent days.

WHO assesses the risk of further spread as high within sub-Saharan Africa and low globally. The trial’s adaptive design means it may not yield definitive results during this epidemic; if the outbreak ends before sufficient patients are enrolled, recruitment can restart during future flare-ups. The next factual milestone to watch is whether the current decline in daily cases holds, and whether the trial can accrue enough participants to generate a reliable signal on the efficacy of these interventions.