Towards curbing the current outbreak of Ebola Virus Disease caused by the Bundibugyo virus in the Democratic Republic of the Congo and Uganda, the World Health Organisation (WHO) has convened experts and advisory groups to advise on treatments and vaccines for the disease.
   
The groups assessed potential vaccines and therapeutics for both prevention and treatment of Bundibugyo virus disease (BVD) and recommended that all identified products should be used exclusively within clinical trials to generate robust data and ensure safe, ethical and effective research.
   
According to WHO, the most promising vaccine candidate identified by the experts is the single-dose rVSV Bundibugyo vaccine being developed by the International AIDS Vaccine Initiative.
   
The global health body explained that the development of the single-dose vaccine candidate would likely require between seven and nine months before it can be assessed through clinical trials for its effectiveness in preventing BVD.
   
WHO convened a series of meetings with its Research and Development (R&D) Blueprint technical advisory groups on candidate vaccines and therapeutics for BVD. It also brought together the Strategic Advisory Group of Experts on Immunisation (SAGE) and its Ebola vaccine working group to advise on the possible role of licensed Ebola vaccines during BVD outbreaks.
   
As there are currently no licensed therapeutics or vaccines specifically approved for the prevention and treatment of BVD, WHO advisory groups considered several candidate products that were deemed promising enough for prioritisation in clinical trials.
   
The organisation said it is working closely with the governments of the Democratic Republic of the Congo and Uganda to facilitate research and evaluation of the identified products.
   
For treatment of confirmed cases, independent experts recommended prioritising three candidate therapeutics for evaluation through clinical trials. These include the monoclonal antibodies MBP134 and Maftivimab, as well as the antiviral drug Remdesivir.
   
WHO also recommended evaluating combination therapy involving a monoclonal antibody and remdesivir.
   
For post-exposure prophylaxis among contacts of confirmed and probable cases, experts identified the oral antiviral obeldesivir as a priority candidate. However, they noted that the success of the approach depends heavily on effective contact tracing, which remains operationally challenging in some affected areas of the Democratic Republic of Congo.
   
The organisation explained that research on post-exposure prophylaxis involves administering tablets of obeldesivir to contacts of infected persons to determine whether it can prevent them from developing Ebola disease.
  
Another candidate vaccine, ChAdOx1 Bundibugyo, being developed by the University of Oxford and the Serum Institute of India, could potentially become available within two to three months for efficacy assessment through clinical trials.
   
However, WHO noted that additional animal data would still be required to support and confirm further prioritisation of the vaccine candidate.

Experts further observed that a single-dose version of the vaccine could be suitable for contacts of Ebola cases, while a two-dose strategy may be considered for high-risk but unexposed groups such as healthcare workers and frontline responders.
   
The convened experts also reviewed the possible role of Ervebo, currently the only licensed Ebola vaccine. According to the WHO, Ervebo is approved for use during outbreaks caused by the most common Ebola virus in Africa from the Orthoebolavirus family. However, it is not licensed for the prevention of BVD, while evidence regarding cross-protection against other Ebola virus species remains limited and inconclusive.
   
WHO therefore recommended that Ervebo should not be used outside carefully designed research settings to enable experts to properly assess its performance against Bundibugyo virus disease.

The WHO R&D Blueprint is a global initiative designed to enable rapid activation of research and development activities during epidemics. Its objective is to fast-track the availability of proven tests, vaccines and medicines capable of saving lives and preventing large-scale health crises.