We aimed to identify the severity and duration of COVID-19 infection on complications after allo-HSCT. Enrolled 179 hospitalized patients with COVID-19 were categorized into long-term infection (> 18 days, n = 90) or short-term infection group (≤ 18 days, n = 89) according to the median duration of COVID-19. The severity of COVID-19 was categorized as asymptomatic infection, mild, moderate, severe, and critical illness according to guidelines of National Institutes of Health. …