Experts convened by WHO advise on candidate treatments and vaccines for Ebola disease caused by Bundibugyo virus

In response to the current outbreak of Ebola disease caused by Bundibugyo virus occurring in the Democratic Republic of the Congo, with cases also reported in Uganda, WHO convened several of its expert and advisory groups. These groups assessed potential vaccines and therapeutics for both prevention and treatment of Bundibugyo virus disease (BVD). The WHO advisory groups recommended that all the products identified and considered be used exclusively within clinical trials to generate robust data and ensure safe, ethical, and effective research. WHO convened a series of meetings with the WHO R&D Blueprint technical advisory groups on candidate vaccines and therapeutics for BVD. In parallel, WHO also convened the Strategic Advisory Group of Experts on Immunization (SAGE) and its Ebola vaccine working group to advise on the potential role of licensed Ebola vaccines during BVD outbreaks.Key recommendations There are currently no licensed therapeutics or vaccines specifically approved for the prevention and treatment of BVD. Nevertheless, WHO advisory groups considered several candidate products that are promising enough to warrant prioritization for evaluation in clinical trials. WHO is now working closely with the governments of the Democratic Republic of the Congo and Uganda to facilitate the implementation of research evaluation of these products. For treatment of cases:For treatment, the independent experts recommended prioritizing three candidate therapeutics for evaluation in research (i.e. clinical trials) among confirmed BVD cases: the monoclonal antibodies MBP134 and Maftivimab®, as well as the antiviral remdesivir. Combination therapy using a monoclonal antibody and remdesivir is also recommended for evaluation.For prevention of cases: For post-exposure prophylaxis among contacts of confirmed and probable cases, the oral antiviral obeldesivir was determined to be a priority candidate, although experts noted that this approach depends on effective contact tracing, which remains operationally challenging in some of the affected areas of the Democratic Republic of the Congo. Research on post-exposure prophylaxis involves giving tablets of obeldesivir to contacts of cases to evaluate whether this prevents them from developing Ebola disease.The most promising candidate vaccine was determined by the experts to be the single-dose rVSV Bundibugyo vaccine (being developed by the International AIDS Vaccine Initiative or IAVI). The development of this single-dose vaccine candidate will likely require 7–9 months before it is ready to be assessed through a clinical trial for its ability to prevent BDV.Another candidate vaccine, ChAdOx1 Bundibugyo (being developed by Oxford University/Serum Institute of India) could potentially become available within 2–3 months for efficacy assessment through a clinical trial.  However, additional animal data are still required to support and confirm further prioritization.