In a ground-breaking study published February 9, 2022, scientists describe how Ebola virus, which can persist in certain areas of the body, can re-emerge to cause fatal disease—even long after treatment with monoclonal antibodies. The research, using a nonhuman primate model of Ebola virus infection, is featured on the cover (image) of the February 9, 2022 issue of Science Translational Medicine. The article is titled “Ebola Virus Persistence and Disease Recrudescence in the Brains of Antibody-Treated Nonhuman Primate Survivors.” Some recent Ebola virus disease outbreaks in Africa have been linked to persistent infection in patients who had survived previous outbreaks, according to the paper’s senior author, Xiankun (Kevin) Zeng, PhD. In particular, the 2021 outbreak of Ebola virus disease in Guinea re-emerged from a persistently infected survivor of the previous major outbreak at least five years ago. However, the exact “hiding place” of persistent Ebola virus and the underlying pathology of subsequent recrudescent, or recurring, disease in survivors—especially those treated with standard-of-care monoclonal antibody therapeutics—were largely unknown. So, Dr. Zeng and his team at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) used a nonhuman primate model, the one that most closely recapitulates Ebola virus disease in humans, to address these questions.