By Kate Merrill

BOSTON (CBS) – With the Omicron variant spreading so easily, at least one expert says cloth masks just don’t cut it anymore.

“The typical cloth mask might be 50 percent effective and that was OK before,” said Dr. Linsey Marr, a professor of civil and environmental engineering at Virginia Tech.

“It doesn’t seem to be enough with Omicron. We have special masks called respirators, such as N95 that offer much greater protection. They’re able to block 95 percent of particles that are either going out of your mouth or that you’re breathing in,” she said.

Dr. Marr studies how viruses move in the air. She says other respirators are also widely available.

“Things like the KN95, which is the Chinese version of the US N95 it has ear loop straps and it’s made out of a special material that’s very efficient at filtering out particles. It also is designed to fit closely to your face. There’s a South Korean version called the KF94 that some people call the boat-shaped respirator,” she said.

Three-ply surgical masks can also help prevent contact with infected droplets.

“There are ways to really improve the performance of a surgical mask by improving its fit. One way is to use some little kind of clips or toggles on the ear loops so that you can tighten it up so it pulls closer to your face,” Dr. Marr said.

The fit is critical for all of these masks, to ensure the strongest possible protection.

“What you need is to have a good seal, especially around your nose, and you want to make sure there aren’t gaps at the sides of your cheeks or at your chin,” said Dr. Marr.

As for kids, Dr. Marr says also choose a good mask that’s comfortable, with good fit and filtration. Some respirators are designed for kids, but N95’s are not designed for younger children.

It’s important to check that a regulating body in the U.S., Chinese or Korean government has approved what you’re purchasing. Counterfeit KN95 respirators are pretty prevalent and the CDC maintains a list of brands selling counterfeit masks.

Kate Merrill