The US Centers for Disease Control and Prevention (CDC) late on Friday revised its guidance for Americans on wearing masks, recommending wearing "the most protective mask you can," although the agency stopped short of calling for nationwide N95 usage.

The CDC clarified in its revised website "that people can choose respirators such as N95s and KN95s, including removing concerns related to supply shortages for N95s." It added that Americans should "wear the most protective mask you can that fits well and that you will wear consistently."