WHO Recommends Ervebo Vaccine Trials for Current Ebola Outbreak in DRC

The World Health Organization (WHO) has recommended prioritizing the Ervebo vaccine in clinical trials to combat the ongoing Ebola outbreak in the Democratic Republic of Congo (DRC). This outbreak has surpassed 4,000 reported infections.

Advisors to the WHO met on July 31 to review vaccine candidates. They concluded that animal trials indicate Ervebo, developed by Merck, provides a degree of protection. Studies on primates showed survival rates up to 75%, and 100% in ferrets. Vaccinated animals also exhibited less severe symptoms and lower viral loads.

While Ervebo is approved for the Zaire Ebola variant, the current DRC outbreak involves the rarer Bundibugyo variant, for which no authorized vaccine or specific treatment exists. Although antibodies generated against Bundibugyo using Ervebo appear weaker than those against Zaire Ebola, experts believe they offer some neutralizing effect.

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Ervebo... offer a certain level of protection.

The WHO's advisory group was formed after the organization declared an international emergency on May 16 due to the DRC outbreak. Initially, they withheld recommendations for Ervebo trials, pending specific research settings. Now, after assessing safety, efficacy, and availability, they deem it safe to proceed with randomized trials, including vaccinating contacts of infected individuals.

This epidemic, the 17th in the DRC, is the fastest-growing on record, surpassing the 2018-2020 outbreak in the country. It has become the second-largest Ebola outbreak in history, though still significantly smaller than the West Africa epidemic of 2014-2016, which caused approximately 11,000 deaths and 28,000 cases.

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but they seem to have some neutralizing effect