The case rates of Bundibugyo Ebola in the Democratic Republic of the Congo (DRC) and Uganda are continuing to increase, as the outbreak spreads substantially faster than previous Ebola outbreaks, making it the second-largest Ebola outbreak on record. As a result, U.S. entry for travelers from these areas is temporarily restricted.
However, there is some good news in that cases are generally less severe and less lethal than during the earliest recorded outbreaks. While the 1976 outbreaks in Zaire and Sudan had mortality rates up to 90%, current case fatality rates average around 50%. The reduction can likely be attributed to greater knowledge about the disease leading to faster diagnostics, advanced medical care and treatments, better preparedness and targeted vaccines, with today’s rates dropping even lower when those who are infected seek out medical help early.
Of critical importance is the development of vaccines, which have helped to control transmission, protect frontline workers, and reduce death rates. Currently, two vaccines are approved for Ebola, but both target the Zaire ebolavirus species, to which most human outbreaks are attributed.
With the Bundibugyo virus causing the current outbreak, for which the existing vaccines are not expected to provide protection, there is a trial in progress on a new vaccine targeting this strain. The vaccine, ChAdOx1 BDBV developed by researchers with the Oxford Vaccine Group, is in phase 1 of a trial to assess its safety and immune response in 50 healthy volunteers aged 18 to 55 years – with the first volunteer vaccinated the last week of July. The team is continuing to recruit and vaccinate volunteers while monitoring participants for the trial.
Subject to regulatory approval, preparations are underway for further clinical studies of the vaccine in Uganda. If early-stage trials are successful, late-stage trials will continue to generate data for emergency use authorization or licensure.
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