Fig. 7: Antiviral activity of combinations of SARS-CoV-2 polymerase and exonuclease inhibitors.

Calu-3 cells, at a density of 5 × 105 cells/well in 48-well plates, were infected with SARS-CoV-2 at a MOI of 0.1, for 1 h at 37 °C. An inoculum was removed and cells were washed and incubated with fresh DMEM containing 10% FBS and the indicated concentration of Remdesivir (RDV) (a), Sofosbuvir (b), Tenofovir (c), and Favipiravir (d), alone and in combination with the HCV NS5A inhibitors. Supernatants were assessed after 48–72 h. Viral replication in the culture supernatant was measured as PFU/mL by titering in Vero E6 cells. Results are displayed as virus titers. The data represent means ± SEM of three independent experiments.