Approximately 85% of affected individuals with vaccination scars were protected against monkeypox by the 1980-abandoned smallpox vaccine . It is anticipated that monkeypox virus will continue to be introduced into human communities from animal sources, and that the average size and duration of monkeypox epidemics will increase as vaccine-derived protection among the human population declines . Diverse rodents and primates in Africa are likely natural reservoirs . Several species of squirrels belonging to the genus Funisciurus are highly susceptible to monkeypox virus infection, while Heliosciurus squirrels and forest-dwelling primates are rarely infected . By using a test called viral plaque assay, most of the organs looked at were found to have the monkeypox virus (MPV) . Multiple detections of the infectious virus MPV in the brains of various animals.