On July 2, 2026, the World Health Organization (WHO) and the Institut National de Recherche Biomédicale (INRB) announced the start of participant enrollment in a clinical trial focused on infections with the Bundibugyo virus, the species responsible for the most recent Ebola outbreak in the Democratic Republic of the Congo (DRC) and Uganda. The trial — termed the Platform adaptive randomized trial for new and repurposed Filovirus treatments (PARTNERS) — is sponsored by WHO and led by INRB. Coordination involves research teams from the Institute of Tropical Medicine in Belgium and the University of Oxford in the United Kingdom, and the initiative is supported by the Africa Centres for Disease Control and Prevention (Africa CDC).
PARTNERS began operations at three sites across the Ituri province in the DRC and had enrolled over 50 Ebola patients at the time of reporting. In addition to the PARTNERS therapeutic platform, several phase 1 clinical trials of candidate preventive medications and vaccines have started at research centers worldwide. WHO confirmed on August 4, 2026, that international trials are underway testing prophylactic agents, vaccines, and targeted treatments for the Bundibugyo strain.
The Bundibugyo species is a distinct Ebolavirus for which there is currently no licensed vaccine or targeted treatment. Clinical care for patients infected with this strain is therefore limited to supportive measures: monitoring blood pressure and bleeding, preventing organ failure, and providing other symptomatic care. WHO reported thousands of confirmed cases and deaths during the outbreak, underscoring the public health urgency for effective countermeasures.
Investigators and WHO representatives have emphasized that, without specific vaccines or therapeutics, outbreak control relies on isolation, contact tracing, and quarantine of exposed individuals. The lack of preexisting, strain-specific interventions motivated the rapid initiation of both preventive and therapeutic clinical research efforts.
Several preventive strategies have entered early-phase trials. A prophylactic oral medication, obeldesivir, previously evaluated for prevention of SARS-CoV-2 infection, has begun testing in the Ituri province. This trial enrolled more than 25 participants considered at high risk because of exposure to the Bundibugyo virus. The obeldesivir regimen under study is a 10-day oral course to determine whether prophylaxis can prevent clinical onset of Ebola following exposure.
Vaccine development for Bundibugyo has progressed to phase 1 testing. The first strain-specific vaccine candidate, ChAdOx1 BDBV, developed by Oxford University with manufacturing by the Serum Institute of India, entered a phase 1 trial in the United Kingdom on July 24, 2026. ChAdOx1 BDBV was produced rapidly using the same vector technology applied in the Oxford–AstraZeneca COVID-19 vaccine; the phase 1 study is assessing safety and immune response in approximately 50 healthy adults aged 18–55.
Moderna has also initiated a phase 1 trial of its mRNA vaccine candidate, mRNA-1469, at three sites in Canada. That trial will similarly evaluate safety and the ability to generate an immune response, with an estimated enrollment of 80 healthy adult participants.
The PARTNERS platform is comparing several therapeutic approaches to determine whether they improve survival in patients infected with the Bundibugyo virus. The trial is assessing the monoclonal antibody therapeutic MBP134, the antiviral remdesivir, and a combined regimen of both agents. MBP134 comprises two human monoclonal antibodies (ADI-15878 and ADI-23774) isolated from a survivor of the 2013–2016 West African Ebola outbreak. Investigators report that MBP134 targets viral binding sites common across multiple Ebolavirus species, including Zaire, Sudan, and Bundibugyo.
Preclinical non-human primate data cited in the trial documentation indicated a reversal of symptoms for a Sudan strain with MBP134 administration. Remdesivir, an antiviral previously used for SARS-CoV-2, has shown efficacy against some Ebolavirus strains in earlier studies and is being repurposed for evaluation against Bundibugyo in this context. WHO and the trial investigators selected these candidates after reviewing existing evidence on potential efficacy and safety, as well as outcomes from previous outbreak responses.
PARTNERS is structured as a platform (adaptive) trial, allowing investigators to introduce additional candidate treatments into the protocol if the WHO Technical Advisory Group determines there is sufficient supporting evidence to justify their inclusion.
WHO has stressed that the clinical evaluation must be conducted without undue haste to ensure robust, reliable assessments of safety and efficacy. The organization indicated that it will take at least several months before meaningful trial results are available. The timeline for PARTNERS' completion will depend on case numbers and participant enrollment at the sites; investigators expressed optimism about brisk enrollment but emphasized that careful data collection and analysis remain paramount.
Clinicians and researchers involved with the effort described the launch of these trials as an important step toward identifying effective treatments and preventive tools for the Bundibugyo strain. While hope exists that the studies may yield actionable results within months to a year, WHO and scientific teams reiterate that definitive conclusions require time and rigorous evaluation according to the trial protocols.