The CDC admitted that cloth masks do not protect against the virus as effectively as other masks.

The Centers for Disease Control and Prevention on Friday clarified their stance on different types of masks, recognizing that the cloth masks commonly worn by Americans do not offer as much protection as surgical masks or respirators.

While this disparity is well known to the general public, the update marks the first time the CDC has explicitly addressed the disparities. The agency’s website also no longer mentions a shortage of respirators.

The change comes as infections with the highly contagious Omicron variant continue to increase. Some experts have said cloth masks are insufficient to protect against the variant, and have urged the CDC to recommend breathing apparatus for ordinary citizens.

The agency didn’t go that far. The updated language now says that “a respirator may be considered in certain situations and by certain people when more protection is needed or desired.”

The previous version of the recommendations stated that individuals can choose to use a disposable N95 respirator instead of a mask “when supplies are available.”

N95 respirators, so named because when used properly they can filter out 95 percent of all airborne particles, were in short supply early in the pandemic. At the time, the CDC and the World Health Organization repeatedly said that ordinary citizens should not wear masks unless they were sick and coughing.

The CDC also said regular surgical masks are “an acceptable alternative” for doctors and nurses when interacting with a patient infected with the coronavirus — a move that angered medical staff.

Critics argued that the recommendations were not based on what would best protect Americans, but were instead motivated by a shortage of N95 respirators.

When the CDC finally recommended masks for ordinary Americans, it emphasized cloth face coverings. It was months before the CDC and WHO admitted that the coronavirus can be carried by tiny droplets called aerosols that can linger indoors for hours.

According to the CDC’s new description of masks, loose-weave fabric products offer the least protection and layered fine-woven products offer more. Properly fitting disposable surgical masks and KN95s – another type of respirator – protect more than any cloth mask, and properly fitted respirators, including N95s, provide the highest level of protection.

The agency urged Americans to “wear the most protective mask you can that fits well and that you will wear consistently.”