Abstract
Pulmonary microthrombosis and vasculitis occur in fatal coronavirus disease 2019. To determine whether these processes occur in other life-threatening respiratory virus infections, we identified autopsy studies of fatal influenza (n = 455 patients), severe acute respiratory syndrome ([SARS] n = 37), Middle East respiratory syndrome (n = 2), adenovirus (n = 34), and respiratory syncytial virus (n = 30). Histological evidence of thrombosis was frequently present in adults with fatal influenza and SARS, with vasculitis also reported.