Severe Acute Respiratory Syndrome-Related Coronavirus Is Inhibited by Interferon-α

Ströher, Ute; DiCaro, Antonino; Li, Yan; Strong, James E.; Aoki, Fred; Plummer, Frank; Jones, Steven M.; Feldmann, Heinz

Current treatment schemes for severe acute respiratory syndrome (SARS) include broad-spectrum antibiotics, glucocorticoids, and ribavirin. We evaluated the susceptibility of the SARS-related coronavirus (SARS CoV) to ribavirin and interferon (IFN)-α in vitro by use of cytopathic effect, plaque assay, and immunoblot analysis. Ribavirin did not inhibit viral growth at concentrations attainable in human serum. In contrast, IFN-α showed an in vitro inhibitory effect starting at concentrations of 1000 IU/mL. In conclusion, ribavirin alone is unlikely to be beneficial in the prophylaxis or treatment of SARS CoV infections. Clinical trials with IFN-α might be justified to determine a beneficial effect on the outcome of SARS.