On Dec. 13, 2023, National Institute of Allergy and Infectious Diseases (NIAID) scientists announced findings published in the Annals of Internal Medicine confirmed that infectious SARS-CoV-2 virus travels in blood throughout the body, infecting cells at various locations.

Scientists affiliated with NIAID and the NIH Clinical Center describe in a case report the discovery of live SARS-CoV-2 in the blood of a 76-year-old woman who died of COVID-19 in fall 2020. Previously, several research teams had identified fragments of the virus in blood and tissue, but never live virus with the ability to replicate.