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Pandemics and Biosecurity
24MAY

Ebola drug trial awaits DRC, Uganda nod

3 min read
16:06UTC

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
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.
Ituri and South Kivu communities / DRC
Ituri and South Kivu communities / DRC
Residents in South Kivu torched a treatment facility when response teams arrived, a signal of community trust deficit that a no-state-apparatus response cannot overcome before it can begin. In Ituri, four healthcare worker deaths at Mongbwalu General Referral Hospital in four days reflect the population's first line of care bearing the outbreak's worst nosocomial burden without species-specific equipment or treatment.
Uganda / Diana Atwine
Uganda / Diana Atwine
Atwine confirmed two imported Bundibugyo cases in Kampala with no onward spread, deployed a mobile laboratory to Kasese on the DRC border, and placed 25 contacts under monitoring before any IHR Temporary Recommendations existed. Uganda's response demonstrates that containment is achievable where a functioning state health authority can compel and protect.
Africa CDC / Jean Kaseya
Africa CDC / Jean Kaseya
Kaseya declared a continental emergency 24 hours before the WHO PHEIC and publicly opposed the US entry ban on 19 May, arguing it punishes countries by passport rather than exposure history. The declaration, Africa CDC's second consecutive pre-WHO move after the 2024 mpox sequencing, reflects an AU strategy to lead early-phase responses independently of Geneva.
United States / HHS
United States / HHS
Washington imposed a 21-day entry ban on nationals of DRC, Uganda and South Sudan on 18 May, including green-card holders, and began enhanced screening for US citizens at George Bush Intercontinental Airport in Houston from 26 May. The ban predated WHO Temporary Recommendations by four days and covered South Sudan despite zero confirmed cases there.
Tedros Adhanom Ghebreyesus / WHO
Tedros Adhanom Ghebreyesus / WHO
Tedros declared the PHEIC on 17 May without the IHR Emergency Committee, then watched the committee's 22 May no-travel-restriction advice arrive four days after the US ban it was meant to prevent. A declaration without operational instructions left states parties with the headline of a global emergency but no guidance on screening, trade or deployment.