Antiviral activities of type I interferons to SARS-CoV-2 infection

There is an urgent need to identify antivirals to curtail the COVID-19 pandemic. Herein, we report the sensitivity of SARS-CoV-2 to recombinant human interferons α and β (IFNα/β). Treatment with IFN-α or IFN-β at a concentration of 50 international units (IU) per milliliter reduces viral titers by 3.4 log or over 4 log, respectively, in Vero cells. The EC50 of IFN-α and IFN-β treatment is 1.35 IU/ml and 0.76 IU/ml, respectively, in Vero cells. These results suggest that SARS-CoV-2 is more sensitive than many other human pathogenic viruses, including SARS-CoV. Overall, our results demonstrate the potential efficacy of human Type I IFN in suppressing SARS-CoV-2 infection, a finding which could inform future treatment options for COVID-19. •Type I Interferons inhibit SARS-CoV-2, the causative agent for COVID-19, in cultured cells.•Treatment with IFN-α or IFN-β at 50 IU/ml reduces viral titers by 3.4-log or over 4-log, respectively, in Vero cells.•The EC50 of IFN-α and IFN-β treatment is 1.35 IU/ml and 0.76 IU/ml, respectively, in Vero cells.•Type I IFNs have been used in clinical therapies and thus could be repurposed in COVID-19 treatment.