IFNA1 and COVID-19: Also, a retrospective multicenter cohort study compared patients who received IFN therapies with those who did not receive IFNs and found association of early IFN-a2b administration (<5 days after admission) with a significantly reduced mortality rate in severe-to-critical cases of COVID-19 although late IFN use was associated with prolonged hospital stay and slower improvement of CT scan compared with non-IFN therapy (84).