VWF and COVID-19: The reasons for the association of severe COVID‐19 with blood type A are unknown, but it has been suggested that this could be caused by O group patients having anti‐A type antibodies [28], that A type glycans could function as co‐receptors for SARS‐CoV‐2 [29] or due to the known effects of blood groups on thrombosis risk due to von Willebrand factor (VWF) levels [30].