John Johnson
MSF Vaccination and Epidemic Response Advisor


On May 15, Uganda and the Democratic Republic of Congo officially declared an Ebola disease outbreak.

What makes this outbreak different and significantly harder to fight is the type of virus that causes Ebola disease. This is the Bundibugyo virus, not the same virus the world knows from the major West Africa epidemic that occurred between 2014 and 2016. That outbreak, and the 2018–2020 one in the DRC, ultimately drove major scientific advances: vaccines and treatments now exist for that specific virus. But for Bundibugyo, no vaccine or treatment has been approved so far.

And there's another difficulty: the ability to diagnose cases quickly. PCR testing requires virus-specific diagnostic cartridges that are currently available in insufficient quantities for Bundibugyo.

So confirming a case quickly is challenging: and without lab confirmation, it is difficult to understand the true size of the current outbreak, identify and follow up the contacts of patients, and limit the spread of the disease.

With no specific treatments or vaccines available, our previous experience in Ebola disease responses has taught us that other factors are crucial to address: contact tracing, isolation of suspected cases, building community trust, infection prevention and control measures, and quick access to healthcare including non-Ebola care. This will require all health partners involved in the response to design an approach adapted to this relatively rare type of Ebola.

On May 17, the WHO declared a Public Health Emergency of International Concern, its highest alert level. Emergency clinical trials for three candidate vaccines and three candidate treatments are now being discussed, with a view to deploying them rapidly in this outbreak.

Across the two previous outbreaks of Bundibugyo virus, the disease killed between 25 and 40 percent of those it infected.
Without an approved vaccine or treatment, efforts to combat the Ebola outbreak in the DRC and Uganda will face significant additional hurdles.