Lung autopsy and plasma samples from people who died of COVID-19 have provided a clearer picture of how the SARS-CoV-2 virus spreads and damages lung tissue. A review conducted by scientists at the National Institutes of Health and their collaborators,  published in Science Translational Medicine, revealed that SARS-CoV-2 directly infected basal epithelial cells within the lungs, impeding their essential function of repairing damaged airways and lungs and generating healthy tissue. The process is different from the way influenza viruses attack cells in the lungs. These findings also make it clear that the virus that causes COVID-19 spreads in the lungs, manipulates the immune system, causes widespread thrombosis that does not resolve, and targets signaling pathways that promote lung failure, fibrosis and impair tissue repair. The study, which included patients who died between March and July 2020, with time of death ranging from three to 47 days after symptoms began, could help predict severe and prolonged COVID-19 cases, particularly among high-risk people, and inform effective treatments.