Health experts have advised that all candidate treatments and vaccines for Ebola disease caused by the Bundibugyo virus should be used exclusively within clinical trials to ensure safe, ethical, and effective research.

A statement made available on Thursday said that the experts were convened by the World Health Organization. According to it, the recommendation comes in response to the current outbreak in the Democratic Republic of the Congo, with additional cases reported in Uganda, and follows assessments by multiple WHO expert and advisory groups.

“WHO convened meetings with its Research and Development Blueprint technical advisory groups on candidate vaccines and therapeutics for Bundibugyo Virus Disease to evaluate options for both prevention and treatment.

“In parallel, the Strategic Advisory Group of Experts on Immunisation and its Ebola vaccine working group reviewed the potential role of licensed Ebola vaccines during BVD outbreaks,” it said.

The statement said that there are currently no licensed therapeutics or vaccines specifically approved for the prevention and treatment of BVD, though several candidate products were identified as promising enough to prioritise for clinical trial evaluation.

It said that for  treatment of confirmed BVD cases, independent experts recommended prioritizing three candidates: the monoclonal antibodies MBP134 and Maftivimab®, and the antiviral remdesivir.

“Combination therapy using a monoclonal antibody and remdesivir was also recommended for evaluation in research settings. For prevention, the oral antiviral obeldesivir was identified as a priority candidate for post-exposure prophylaxis among contacts of confirmed and probable cases,” it said.

According to it, experts noted that post-exposure prophylaxis with obeldesivir depends on effective contact tracing, which remains operationally challenging in some affected areas of the DRC.

It said that the  most promising vaccine candidate was the single-dose rVSV Bundibugyo vaccine being developed by the International AIDS Vaccine Initiative, though it is expected to require seven to nine months before it is ready for clinical trial assessment.

It said that another candidate, ChAdOx1 Bundibugyo from Oxford University and the Serum Institute of India, could potentially be available within two to three months for efficacy testing, pending additional animal data.

“Experts suggested a single-dose approach for contacts of cases, while a two-dose strategy might be considered for high-risk but unexposed populations such as health-care workers and frontline responders.

“The groups also reviewed Ervebo, the only licensed Ebola vaccine, which is approved for outbreaks caused by the most common Ebola virus in Africa but is not licensed for BVD and lacks conclusive evidence of cross-protection,” it said.

The statement said that WHO recommended that Ervebo should not be used outside carefully designed research settings to allow its performance against BVD to be properly assessed.

“WHO, the governments of the DRC and Uganda, Africa CDC, ANRS Emerging Infectious Diseases, and other partners are now working to develop protocols for clinical field trials.

“While continuing to rely on established Ebola response measures like surveillance, contact tracing, isolation, testing, community engagement, and safe burials to stop transmission,” it said.

(NAN)