Inhibition of novel ß coronavirus replication by a combination of interferon-a2b and ribavirin

Falzarano, Darryl; de Wit, Emmie; Martellaro, Cynthia; Callison, Julie; Munster, Vincent J.; Feldmann, Heinz

To determine the potential antiviral effect of IFN-a2b and ribavirin on nCoV isolate hCoV-EMC/2012 replication, susceptible cells were infected with hCoV-EMC/2012. Following 1 h absorption, infected cells were treated with either IFN-a2b or ribavirin. In Vero cells, IFN-a2b reduced the cytopathogenic effect (CPE) starting at a concentration of 250 U/ml and completely eliminated CPE at 1000 U/ ml and above ( Figure 1A ). Ribavirin reduced CPE starting at a concentration of 100 mg/ml and completely eliminated CPE at 200 mg/ ml and above ( Figure 1A ). Viral protein levels, as measured by nucleocapsid protein expression in cell lysates, were also reduced in the presence of increasing levels of IFN-a2b, with a reduction starting at 250 U/ml ( Figure 1B) . In response to ribavirin treatment, a reduction in nucleocapsid protein expression was observed at 50 mg/ml, but did not appear to be dose dependent ( Figure 1B ).