An experimental Ebola vaccine tested on humans has been shown to provide complete protection against the fatal disease, scientists said in research published Thursday. The vaccine, which has not yet been approved by any regulators but is already being stockpiled as a cure, has become the first one since Ebola was discovered in 1976 to effectively fight the terrifying illness. The 2014 outbreak of the virus, which claimed 11,000 lives in Africa and a handful in Europe and the U.S., is credited with providing the motivation necessary for the new vaccine. While that outbreak was declared over in March 2016, isolated cases of the virus continue. Health workers and scientists have hailed the new vaccine, known as rVSV-EBOV, as a newfound hope against future outbreaks. “While these compelling results come too late for those who lost their lives during West Africa’s Ebola epidemic, they show that when the next outbreak hits, we will not be defenseless,” Marie-Paule Kieny, the Lancet study’s main author and the World Health Organization’s assistant director-general for health systems and innovation, was cited saying by The New York Times. The study was conducted among 11,841 residents in Guinea last year. Of the 5,837 people who were given the vaccine as part of the study, not a single one caught the virus, though 23 people who did not get it were infected, researchers said. The study was led by the World Health Organization, the Guinean Health Ministry, Norway’s Institute of Public Health, among other organizations.