Starting in 2014, the Ebola epidemic ravaged West Africa, killing more than 11,300 people in Sierra Leone, Liberia, and Guinea. The public-health crisis officially ended by 2016, but at the tail end of the outbreak in Guinea, researchers tested a vaccine that has shown itself to be “100 percent” effective in preventing one of the most virulent strains of the disease, according to results published Thursday in The Lancet.
The study of the vaccine — which has unpronounceable name of rVSV-ZEBOV — included more than 11,800 Guineans. A total of 5,837 people received the vaccine; zero came down with Ebola ten or more days later. Of the remaining people, 23 who did not get the vaccine came down with Ebola ten or more days later. There are a few caveats: The injection only prevents against one type, the Zaire strain of Ebola, which is the one that ravaged West Africa, and it’s unclear how long-lasting even that protection may be.
The vaccine, which the New York Times says was developed a decade ago by the Public Health Agency of Canada and the United States Army, hasn’t yet officially been approved for use, though it’s being fast-tracked and could be available by 2018, reports the BBC. And Merck, the licenser of rVSV-ZEBOV, has stockpiled 300,000 doses in case of another mass outbreak.