F2 and COVID-19: These subjects are also more likely to have complications of acute respiratory distress syndrome (6.76% vs. 2.08%), progression to the severe and critical forms of COVID-19, more frequently need to use mechanical ventilation and to be admitted in intensive care units (ICU) (6.76% vs. 2.08%) (28), besides prolonged prothrombin time (13.1 vs. 12.5 s) (30).