Which Viruses Woke Up and WhenEleven reactivated viruses were detected within the first 40 days after hospital admission. Among 1,154 patients hospitalized with COVID-19, dormant viruses reactivated in nearly half, and that reactivation correlated with disease severity, inflammation and clinical outcomes. Eleven were detected, most commonly herpes simplex virus 1 and anelloviruses, with Epstein-Barr virus, cytomegalovirus and enteroviruses found less often. Does this prove the reactivated viruses caused severe COVID or long COVID? There is no evidence that testing or treating reactivated viruses improves outcomes, and antivirals carry meaningful risks.