IFNA2 and COVID-19: For FPV, two studies in COVID-19 outpatients reported a median time to viral clearance of 10 days (n = 112) versus 8 days with placebo,34 and more rapid viral clearance with FPV (6.0 days; n = 83) than with control (14.0 days; n = 44; umifenovir plus intranasal interferon alpha-2b or hydroxychloroquine).35