Antiviral activity of prepared powders (IMAGE) Tokyo Institute of Technology Caption (a) Antiviral activity of prepared powders against coronavirus and photographs showing the change in plaque number of coronavirus after four hours: (b) control and (c) with CMO. Credit Material letters Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.