(AFP) — WHO vaccine experts Friday recommended a full-scale human trial of the only existing approved Ebola vaccine to see if it offers cross-protection against a deadly strain spreading in the Democratic Republic of Congo. “The members recommended Ervebo, the only licensed Ebola vaccine, be prioritized for inclusion in a randomized clinical trial in the context of the ongoing outbreak,” a WHO statement said. Nonetheless, a specific Bundibugyo vaccine remains the preferred option for fighting the current outbreak, they stressed. “This is already the largest Ebola outbreak in DRC’s history, and could well become the largest outbreak ever,” said Gavi chief executive Sania Nishtar. “Given the terrible toll on communities and frontline workers, we are encouraged that the approved Ebola vaccine Ervebo … could help reduce severe illness and deaths.”