To fight against COVID-19 and its variants, the Centers for Disease Control and Prevention has modified its masking guidelines.

According to the most recent update from the CDC, cloth and surgical masks provide the least amount of protection against the coronavirus, while respirators provide the best protection, such as on public transit or in crowded environments.

Respirators, which are often mistakenly referred to as "masks" due to their appearance, are personal protection equipment that are built to a specific standard and designed to keep harmful airborne particles out of the lungs.

Respirator standards in the U.S. are managed by the National Institute for Occupational Safety and Health (NIOSH), which consider three factors: filter efficiency, breathing resistance, and fit.

A filter that meets the N95 standard (equivalent to Europe's FFP2) must collect at least 95% of particles in the most penetrating size range at high flow rates.

A filtering facepiece respirator (FFR) is one that is comprised entirely of filtering material, as opposed to having layers for waterproofing, for example. An FFR can be worn multiple times before it is discarded.

FFRs lose their capacity to fit well after 20 uses, according to research, due to strap stretching or failure of the nose clip or edge components.

While the N95 and KN95 masks offer the most protection, the CDC stresses the significance of using a mask that fits properly and does not have any gaps around the nose or sides.

No gaps should exist between your face and the respirator, particularly around the nose and chin. To make a tight seal, secure the nose clip and wrap both straps around your head, adjusting as needed.

If the facepiece collapses somewhat as you breathe, the respirator is likely to fit comfortably. Make it a habit to check your own seals before every use.

Because of Omicron's rapid growth in COVID transmission, the masks that people wear have received increasing attention.

"Cloth masks are little more than facial decorations," CNN Medical Analyst Dr. Leana Wen, an emergency physician and professor at George Washington University, said. "There's no place for them in light of Omicron."

According to the CDC's new advice, "any mask is better than no mask" as long as it is properly fitted with multiple layers of protection. People should also wear a disposable mask underneath and a cotton mask on top of their masks, according to the rules.

In addition, the CDC updated its guidelines to address concerns regarding N95 mask supply restrictions.

The Biden administration previously announced that N95 masks would be distributed for free to assist combat the rise in COVID-19 cases in the U.S.