In hospitals, viruses are everywhere. Masks are not.

As a result, in emergency rooms at many hospitals — like Banner-University Medical Center Tucson, Ariz., and Kaiser Permanente Sunnyside Medical Center, outside Portland, Ore. — Covid patients rub shoulders with people elderly, pregnant women and people with illnesses such as diabetes which puts them at high risk if infected.

Very few hospitals treating primarily immunocompromised patients, such as City of Hope, a cancer treatment center in Los Angeles, have maintained universal masking. But some of the nation's most prestigious hospital systems don't require masks, even in their cancer centers, where severely immunocompromised patients like Mx are housed. Grace receives infusions.

“Do what you want — that's basically what the CDC guidelines say, at this point, in terms of universal masking,” said Jane Thomason, chief industrial hygienist for National Nurses United, which represents nearly 225,000 registered nurses.

The guidelines give hospitals “permission to prioritize profits over protecting nurses and patients,” Thomason said. The union has called for stronger protections, including the use of N95 respirators, to protect health care workers, patients and visitors.