By Nancy Clanton, The Atlanta Journal-Constitution

As the delta and other coronavirus variants emerge, AMA again stresses importance of face coverings

As kids return to school and various coronavirus variants emerge, the Atlanta-based Centers for Disease Control and Prevention is once again recommending people wear a mask in public, regardless of their vaccination status.

The American Medical Association is also stressing recommendations it made early in the pandemic: Make sure your mask fits correctly and double up on face coverings.

Adding layers of material to a mask or wearing two masks reduces the number of respiratory droplets that come through the mask, the AMA wrote.

If one person is using a cloth mask over a surgical mask while the other person is not, it has been shown to block 85.4% of cough particles, according to a study published in JAMA Health Forum. When both people are double masking, potentially infectious aerosols decrease by 95%.

There are exceptions, however. Wearing two disposable masks is not effective, because such masks are not designed to fit snugly on the face. And wearing two KN95 or N95 masks isn’t necessary, because just one can filter 95% of particles and fit snugly to your face, so there is no need to wear two.

After experimenting with varying techniques for mask effectiveness, the agency concluded that wearing a cloth mask over a surgical mask — along with using a mask filter or wearing a nylon covering over a mask — are effective options to improve a mask’s fit and decrease exposure to aerosols that could cause infection, The Atlanta Journal-Constitution’s Kiersten Willis wrote.

The newer coronavirus variants are far more transmissible and lead to higher severity of symptoms, said AMA member Megan Srinivas, MD, MPH, an infectious diseases specialist and translational health policy research fellow at the University of North Carolina at Chapel Hill. The increased transmissibility, not knowing how effective the vaccines are against the variants and “the fact that more variants might pop up as this goes on makes it more important than ever that we continue to mask up.”

“The only way we’re really going to be able to rely on herd immunity is if we can bring the community transmission rates down low enough where the importance of prevention is more important than control,” she said. “With our positivity rates in the United States, we’re still in that aspect of — in order to control, we really need masking to be in place.”