Can a vaccine built for one Ebola virus stop another? The World Health Organization is about to find out

The World Health Organization (WHO) has recommended prioritising the Ervebo vaccine for testing in a clinical trial in the Democratic Republic of the Congo. The vaccine was originally developed to protect against Zaire ebolavirus, the species responsible for the devastating west African epidemic just over a decade ago. It was not designed for the Bundibugyo species responsible for the current outbreak – which raises the question of why scientists are considering it at all. The current Ebola…