Is the new Ebola vaccine too good to be true?

Ebola is on the run: the number of cases dipped below ten a week recently, and a few days ago investigators announced in the prestigious journal The Lancet that a new Ebola vaccine was “100% effective.”

In response, global health authorities are starting to sound a little giddy. “We believe that the world is on the verge of an efficacious Ebola vaccine,” said Marie Paule Kieny, the World Health Organization’s assistant director-general for health systems and innovation (and a senior author on the paper). “It could be a game changer.”

She’s right: this is wonderful news, and a great testament to human ingenuity. A genetically engineered hybrid of the benign vesicular stomatitis virus and the Zaire strain of Ebola, together called rVSV-ZEBOV, was tested in a multi-site clinical trial conducted amid a massive aid response in Guinea, one of the poorest countries in Africa. The scientific and logistical acrobatics required to pull this off boggle the mind.

Yet, for three reasons, we cannot know if the vaccine really worked, or how well. 

To read more, check out my new post over at The Conversation.