Inhibition of severe acute respiratory syndrome coronavirus replication by niclosamide

Antiviral agents are urgently needed to fight severe acute respiratory syndrome (SARS). We showed that niclosamide, an existing antihelminthic drug, was able to inhibit replication of a newly discovered coronavirus, SARS-CoV; viral antigen synthesis was totally abolished at a niclosamide concentration of 1.56 muM, as revealed by immunoblot analysis. Thus, niclosamide represents a promising drug candidate for the effective treatment of SARS-CoV infection.