A Study By The University Of Virginia Found That Ensitrelivir, A Drug Already Approved In Japan, Could Help Prevent Covid-19 In People Exposed Within Households. In A Trial With Over 2,000 Participants, People Who Took The Drug Were 67% Less Likely To Develop Covid Compared To Those Taking A Placebo. Researchers Say The Drug Could Provide A Critical Tool For Preventing Covid In High-Risk Populations If Approved In The U.S.