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, Ph.D. 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 Zeng and his team at the U.S. Army Medical Research Institute of Infectious Diseases used a nonhuman primate model, the one that most closely recapitulates Ebola virus disease in humans, to address these questions.