Compound targets essential viral enzyme and prevents replication in cells.     The experimental drug TEMPOL may be a promising oral antiviral treatment for COVID-19, suggests a study of cell cultures by researchers at the National Institutes of Health. TEMPOL can limit SARS-CoV-2 infection by impairing the activity of a viral enzyme called RNA replicase. The work was led by researchers at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). […]