WHO Recommends Testing Ebola Vaccine Against Bundibugyo Virus in Congo

World Health Organization experts recommended prioritizing the licensed Ebola vaccine Ervebo for evaluation in a randomized clinical trial during the ongoing Bundibugyo virus disease outbreak in the Democratic Republic of the Congo, according to a statement released by the organization. The Technical Advisory Group on candidate vaccine prioritization issued the recommendation after reviewing preliminary animal study data showing that the vaccine offered some level of cross-protection against the virus, particularly against death.

Evaluating Ervebo for Bundibugyo Virus Disease

Ervebo stands as the only licensed Ebola vaccine available globally, but its current regulatory approval covers Ebola virus disease caused by the Zaire ebolavirus rather than the Bundibugyo strain. According to the WHO advisory group, the vaccine showed no safety concerns when considered for potential use in a trial where contacts of active cases receive doses during an outbreak. Experts noted that while animal studies point to cross-protection against death, the actual effectiveness of Ervebo against Bundibugyo disease transmission and clinical outcomes still requires rigorous demonstration through human research.

Advisory Group Timeline and Research Framework

The WHO convened its advisory groups after declaring the outbreak in the Democratic Republic of the Congo a Public Health Emergency of International Concern. On July 31, members of the technical advisory group met for the third time to evaluate the latest preliminary data sets. Prior to these animal study findings, the advisory group had strongly recommended that Ervebo not be administered outside carefully controlled research protocols until its specific performance against the Bundibugyo virus could be thoroughly assessed.

Despite the push to evaluate Ervebo, the WHO advisory group emphasized that a vaccine specifically manufactured to target the Bundibugyo virus remains the preferred long-term option. However, comprehensive preliminary data regarding candidate vaccines specifically designed for the Bundibugyo strain are not yet available, prompting the current trial recommendation for Ervebo.

Frequently Asked Questions

What is Ervebo currently licensed to treat?

Ervebo is licensed to protect against Ebola virus disease caused by the Zaire ebolavirus.

Why is the WHO considering Ervebo for the Congo outbreak?

Preliminary animal studies reviewed by the WHO Technical Advisory Group showed that Ervebo offers some level of cross-protection against death from the Bundibugyo virus.

Has Ervebo’s effectiveness against Bundibugyo been proven in humans?

No. WHO experts stress that Ervebo’s actual effectiveness against Bundibugyo disease and transmission still needs to be demonstrated through clinical research.