CDC warns loosely woven cloth masks are 'least protective' against COVID

Any mask is better than no mask. But loosely woven cloth masks provide the least amount of protection and Americans in some cases might want to opt for higher quality masks like KN95 and N95 respirators, the Centers for Disease Control and Prevention wrote Friday in updated online guidance.

"Wearing a highly protective mask or respirator may be most important for certain higher risk situations, or by some people at increased risk for severe disease," the CDC stated.

The updated guidance comes after weeks of health experts urging Americans to upgrade their masks in the face of omicron, warning that cloth masks are not effective enough at stopping the highly transmissible variant from spreading.

But with much of the public reluctant to wear a mask at all, the CDC recommendation stops short of calling on Americans to choose one mask over the other, maintaining that any mask is better than no mask. The CDC also argues that higher quality masks can be less comfortable, and if a person takes it off, they are left with no protection.

"What I will say is the best mask that you can wear is the one that you will wear and the one you can keep on all day long that you can tolerate in public indoor settings and tolerate where you need to wear it," Dr. Rochelle Walensky, the CDC director, told reporters this week.

N95 and KN95 masks can be costly and harder to find, even as the U.S. government has built up a stockpile of 737 million N95s to ensure first responders don't run out. President Joe Biden said this week he is developing a plan to make the higher quality masks more widely available.

"Next week we'll announce how we're making high-quality masks available to the American people for free," Biden said.

In its earlier guidance, the CDC urged Americans not to purchase surgical N95 masks so as to save them for health care workers. However, it noted that "basic disposable" respirators can be an option so long as supplies are available.

While this latest guidance stops short of calling on people to wear a certain type of mask, it includes more information about why a person might opt for a nonsurgical N95 or a KN95. It also suggests wearing a disposable surgical mask with a cloth mask over it to improve the fit.

"Some masks and respirators offer higher levels of protection than others, and some may be harder to tolerate or wear consistently than others," the CDC stated in the updated guidance. "It is most important to wear a well-fitted mask or respirator correctly that is comfortable for you and that provides good protection."