The Biden administration will significantly loosen federal mask-wearing guidelines to protect against COVID-19 transmission on Friday, according to two people familiar with the matter, meaning most Americans will no longer be advised to wear masks in indoor public settings. The Centres for Disease Control and Prevention on Friday will announce a change to the metrics it uses to determine whether to recommend face coverings, shifting from looking at COVID-19 case counts to a more holistic view of risk from the coronavirus to a community. Under current guidelines, masks are recommended for people residing in communities of substantial or high transmission — roughly 95 per cent of U.S. counties, according to the latest data.