The Partnership for Research on Ebola VACcination (PREVAC) immunisation study began 1 year ago, when the Ebola virus was re-emerging in the DRC. Thanks to more than 2,000 adults and children in the study in Guinea and Liberia, this international clinical trial is evaluating the safety and immunogenicity of two potential vaccines against the Ebola virus. The results will be decisive in preventing a new epidemic.