Medieval manuscripts are "biological time capsules" for deadly sheeppox virus

Scientists extracted and sequenced sheeppox virus DNA from the animal skins used as parchment in medieval manuscripts, revealing continuous viral presence in Eurasian sheep for at least 3,500 years. The genetic record aligns with historical accounts—from first-century Roman descriptions of pustules to medieval references to “pockes” and 19th-century outbreaks—showing periodic resurgence and high mortality across France, Spain, England, and Britain.