NextBillion - An Initiative of the William Davidson Institute at the University of Michigan

Monday, January 9, 2017

An Ebola vaccine that has been in development for 15 years has been shown in a clinical trial to be up to 100 percent effective at preventing the deadly virus. But it won’t stop sporadic cases from popping up, nor will it be immediately available to some who are most vulnerable to the virus.

Marie-Pierre Preziosi, head of the Initiative for Vaccine Research at the World Health Organization, which led the trial, says the vaccine is only meant to be used to stop the spread of an existing outbreak. Once WHO identifies new Ebola cases, only people most at risk of being exposed to a sick person—like family members, health-care providers, or sanitation workers—would receive the vaccine if it’s approved.

Preziosi says the vaccine won’t be administered as a preventive vaccine on a large scale, like vaccine campaigns for smallpox or polio, because there’s not enough data to show how long the vaccine’s protection lasts. If the vaccine is approved by drug regulators, it wouldn’t be used for a “long-term strategy” to thwart new Ebola cases, she says.