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Pandemics and Biosecurity
2JUN

Ebola drug trial awaits DRC, Uganda nod

3 min read
09:17UTC

WHO is sponsoring a trial of remdesivir and the antibody cocktail MBP134 for Bundibugyo Ebola, but it cannot dose anyone until the DRC and Uganda grant regulatory approval.

ScienceDeveloping
Key takeaway

The most promising Ebola therapeutic is stalled by national approvals that conflict is making harder to secure.

WHO is sponsoring a trial of two existing therapeutics for Bundibugyo Ebola: remdesivir, an antiviral, and MBP134, a monoclonal antibody cocktail (engineered proteins that bind and neutralise the virus) from Mapp Biopharmaceutical that is active across Ebola species 1. In animal studies MBP134 gave 100% protection even when given up to eight days after infection 2. The trial has not begun dosing; it awaits regulatory approval from the DRC and Ugandan governments 3. This trial is the concrete answer to the gap flagged when the emergency was declared, when WHO confirmed no licensed countermeasure exists for this species and its R&D Blueprint had already named the Bundibugyo therapeutic gap .

National regulators in the DRC and Uganda must clear an investigational protocol, secure informed consent and stand up trial sites before any patient is dosed, and those are exactly the functions that conflict and a torched clinic erode. A trial needs a stable site, a traceable cohort and a chain of custody for samples; the South Kivu crossing and the 21% tracing ceiling in Ituri make all three harder to guarantee. The therapeutic that could cut the fatality rate is gated behind administrative steps that the outbreak's geography is actively dismantling.

No Bundibugyo-specific vaccine has reached even Phase 1. A ChAdOx-platform candidate is two to three months from producing trial doses but lacks safety data; an rVSV-platform candidate is six to nine months out 4 5. ChAdOx and rVSV are the two viral-vector designs behind the Oxford COVID and licensed Zaire-Ebola vaccines. Roughly 2,000 doses of Ervebo, licensed only for Zaire ebolavirus, already sit in the DRC, and GAVI says they could be used in a trial if WHO experts judge it worth testing against a different species 6. Every route to a vaccine here is measured in months, not days.

Deep Analysis

In plain English

The most promising treatment being tested against this type of Ebola is MBP134, a cocktail of laboratory-made antibodies developed by a company called Mapp Biopharmaceutical. In animal studies, it protected 100% of infected subjects even when given up to eight days after infection. It also works against multiple types of Ebola, including Bundibugyo. The problem: it cannot be given to human patients yet because the governments of DRC and Uganda have not yet approved the trial. Clinical trials in outbreak conditions require oversight to protect patients, who may be too sick to give fully informed consent. A second antiviral, remdesivir (also used in Covid-19 treatment), is being trialled alongside MBP134. An Ebola vaccine designed for a different species, Ervebo, has about 2,000 doses stockpiled in DRC; scientists are debating whether to test it here, even though it was not made for this type of virus.

Deep Analysis
Root Causes

No licensed vaccine or treatment exists for Bundibugyo ebolavirus because the two prior outbreaks produced only 169 combined cases across 2007 and 2012, insufficient patient numbers and market incentive for a full regulatory trial programme.

Mapp Biopharmaceutical developed MBP134 under the US Department of Defense's medical countermeasures programme for filovirus threats, not through a commercial development pathway, which means compassionate-use access depends on US regulatory frameworks that cannot bind DRC or Uganda authorities.

The ChAdOx-platform Bundibugyo vaccine candidate being two to three months from trial doses reflects the same market-size problem: Oxford developed the platform using prior MERS and COVID-19 investments; the Bundibugyo-specific insert requires immunogenicity data that cannot be obtained without an outbreak. The outbreak has now arrived, but the trial cannot start before safety data that takes months to generate.

First Reported In

Update #4 · Ebola triples, response misfires

NBC News· 24 May 2026
Read original
Different Perspectives
Imperial College London / Cori and Ferguson
Imperial College London / Cori and Ferguson
Anne Cori and Neil Ferguson place the case-fatality ratio at 30 to 40 per cent and read the 6.8-to-1 suspected-to-confirmed ratio as evidence that the laboratory figure understates true lethality. Many people die before a swab reaches them.
Uganda / Diana Atwine
Uganda / Diana Atwine
Diana Atwine's ministry traced the imported Kampala index case and leant on protocols rehearsed in Uganda's 2022 Sudan ebolavirus response, which contained 142 cases in 113 days without a vaccine. Nine confirmed cases now test whether that playbook holds across two districts.
United States / HHS
United States / HHS
Washington imposed a 21-day entry ban on DRC, Uganda and South Sudan nationals against WHO advice, and sought a 50-bed quarantine site in Nairobi that a Kenyan court suspended on 29 May. The posture rests on a thin federal bench with vacant senior public-health roles.
WHO / Tedros Adhanom Ghebreyesus
WHO / Tedros Adhanom Ghebreyesus
Tedros Adhanom Ghebreyesus called the outbreak 'outpacing us' on 25 May and visited Ituri on 28 May, arguing that stopping transmission depends entirely on humanitarian access. WHO opposes any restriction of travel to or trade with DRC or Uganda.
Africa CDC / Jean Kaseya
Africa CDC / Jean Kaseya
Jean Kaseya declared the continental emergency before WHO and opposed the US travel ban as punishment by passport rather than by exposure. The Africa CDC raised nearly $500 million in days and frames the response as African-led, coordinated from Addis Ababa rather than waiting on Geneva.
European Union / ECDC
European Union / ECDC
ECDC activated an EU Health Task Force, assessed European Bundibugyo import risk as very low, and flagged the recombinant clade Ib/IIb mpox strain in four countries as a surveillance watch item. Both calls reflect the same post-2024 IHR mandate: ECDC acts as a continental early-warning layer rather than waiting for WHO Disease Outbreak News guidance.