WHO Advances Phase 3 Ebola Vaccine Trial in Congo

The World Health Organization is working with authorities in the Democratic Republic of the Congo to accelerate the launch of a Phase 3 clinical trial for an Ebola vaccine, a critical step as the country battles its largest and deadliest outbreak on record. The trial, which could begin as early as mid-September, will initially test Merck's Ervebo vaccine, which is approved for a different Ebola species, to see if it offers cross-protection against the Bundibugyo ebolavirus strain driving the current crisis.

As of August 10, the outbreak in the DRC's Ituri province has confirmed more than 4,500 cases and over 2,060 deaths, according to WHO Director-General Tedros Adhanom Ghebreyesus. He warned that at its current pace, the epidemic is on track to surpass the 2014-2016 West African outbreak, the deadliest in history. The Bundibugyo species is distinct from the Zaire ebolavirus for which existing vaccines were developed, and no approved vaccine currently exists for it.

The planned Phase 3 trial represents a parallel strategy to the early-stage human trials already underway for vaccines specifically targeting Bundibugyo. Moderna has begun a Phase 1 trial of its mRNA vaccine...