The Centers for Disease Control updated its mask guidance last week, recommending people wear N95 or KN95 masks.
“As we are entering year three of the pandemic, we’re getting more and more data to suggest that a surgical medical-grade mask or an N95 mask does a better job at doing these things of prevention of respiratory droplets going to the people around you than, say, a simple cloth mask,” said Dr. Adi Shah, a consultant with the Mayo Clinic Division of Infectious Diseases. “The virus particles are carried on droplets that are made from our mouth or nose.”
“When you have high community transmission coupled with a highly efficient variant for transmission, of course, your layer of protection that you may need could be higher,” Shah added.
Previously, the public was told to avoid N95 masks because there was a shortage and they were needed in medical facilities.
“We definitely had a shortage of the N95 masks,” said Dr. Scott Joy, who is the chief medical officer for HealthONE Physician Services Group. “There was a lot of issues with the supply chain to make sure we had enough of those really tight masks that were very effective to use in the situations where they were most effective.”
While the highly-effective masks are still in high demand, there are more available.
“Now that we have more inventory and we’ve got a very transmittable virus, it just makes sense to take every opportunity to reduce the concentration of virus that might be getting into your airways,” Joy said.
All masks aren't created equal. Some of them provide much more protection, doctors say.
"Cloth masks are not as good in terms of filtration or fit. Surgical masks have a better filtration but they’re also not fitted. N95 masks are put through rigorous conditions for testing,” said Dr. Abraar Karan, an infectious disease doctor at Stanford University.
Karan worked with the World Health Organization’s Independent Panel for Pandemic Preparedness and Response. He said N95 masks are the best option. He said they filter out 95% of particles in the air.
“There's this harder shell cup style which we do use in the hospital, and then there is a softer shell style that we also use in the hospital,” he said.
Before people go out and buy a box of N95 masks, they should make sure that they are made properly.
“If you're seeing just a plain generic box that says N95 masks without some other documentation that says it has gone through a system of verification, I probably wouldn't pick that up,” Joy said.
The next best thing is a surgical mask.
“It’s not fitted at all, it's just a loose mask. You have an opening on the side here laterally, so things can go in and out,” Karan said.
Cloth masks rank lower for protection, but Karan said tolerability also plays a factor.
“If you're not able to tolerate a mask that has higher filtration, then it's better to wear a mask you can tolerate and keep on,” he said.
Bottom line: The CDC says to wear a mask that fits well and that can be worn often.
“If you have millions of people wearing something that's 50% effective versus millions of people wearing something that's 85 or 90% effective, that’s a big deal," Karan said. "That really compounds, adds up, and that means you slow spread very quickly."