Omicron, which World Health Organization officials warned is spreading faster than any COVID-19 variant, is again calling into question the effectiveness of reusable cloth masks.
Peter Jüni, MD, head of Ontario’s Science Advisory Table in Canada, said in a Dec. 16 interview with CTV that single-layer cloth masks offer minimal filtration.
"The minimum would be a double-layered cloth mask that has been washed before so that it is denser and filters better and really fits well," Dr. Jüni said.
Trish Greenhalgh, professor of primary health care services at the University of Oxford, told Bloomberg that double- or triple-layer cloth masks made of a mix of materials can be more effective than single-layer masks, but most cloth masks are just "fashion accessories."
While N95 respirator manufacturers have to make sure they filter out 95 percent of particles, Ms. Greenhalgh said cloth masks do not meet any kind of health standards. She added masks need to cover the mouth and nose properly, and the wearer needs to be able to breathe easily.
Leana Wen, MD, CNN's medical analyst, urged people in a Dec. 20 segment to wear high-quality, three-ply surgical masks.
“Cloth masks are little more than facial decorations," Dr. Wen said. "There’s no place for them in light of omicron."