By MIKE STOBBE
AP Medical Writer
NEW YORK (AP) — U.S. health officials have updated their mask guidance, encouraging more Americans to wear N95 or KN95 masks to slow the spread of the coronavirus. The Centers for Disease Control and Prevention posted the updated guidance late Friday afternoon. Those kinds of masks are considered better at filtering the air. In the past, they were in short supply. So CDC officials previously said they should be prioritized for health care workers. But supplies have improved, and CDC officials say more Americans should consider them.