The World Health Organisation (WHO) has warned against assuming that Ervebo®, the only licensed Ebola vaccine, can protect people against the Bundibugyo virus (BDBV) responsible for the ongoing outbreak.
In updated emergency guidance issued on August 31, WHO said animal, immunological and observational evidence indicates that Ervebo may provide some cross-protection against BDBV. However, the agency stressed that there is currently insufficient evidence to determine whether the vaccine offers meaningful protection in humans.
WHO recommended that any use of Ervebo against BDBV should take place only under research protocols, particularly through a ring randomised controlled trial designed to generate reliable data on its effectiveness.
The agency also stressed that established Ebola outbreak-control measures must continue while research into the vaccine’s effectiveness is under way.
WHO urged health authorities and response teams to communicate clearly that the effectiveness of Ervebo against BDBV remains uncertain, warning against creating a false sense of protection.
The organisation further called for faster development of vaccines specifically targeting BDBV, alongside other medical countermeasures.
The warning comes as the Democratic Republic of the Congo battles its largest and deadliest Ebola outbreak, with the Bundibugyo species responsible for the current epidemic. WHO Director-General Tedros Adhanom Ghebreyesus said on September 2 that the response must be scaled up as transmission chains remain difficult to trace.
