CDC: Wearing a mask protects both you, others

When the White House coronavirus task force first recommended mask-wearing April 3, officials emphasized this was not about you. It was about others. Your mom, dad, other family members. Friends. The older woman who always smiles at you at the grocery store, the immunocompromised dad coaching your kid’s basketball team.

Now, a growing body of science suggests that by wearing a mask to prevent spreading the virus, you may be protecting yourself, too. It is further evidence that knowledge about masks, and their benefits, continues to evolve — much like understanding of the pandemic more broadly.

The CDC publicly acknowledged that for the first time, writing in a scientific bulletin posted to its website this week, “the benefit of masking is derived from the combination of source control and personal protection for the mask wearer.” Masks are neither completely selfless nor selfish — they help everyone.

John Brooks, chief medical officer for the CDC’s coronavirus response, said therewas an urgency to explain this clearly, because the widespread wearing of face coverings can help avoid a return to lockdowns.

Because the CDC cannot impose mandates, the agency wants the public to understand masks are “good for them,” Brooks said.

“Wearing a mask blocks you from inhaling potential virus-containing particles in the air,” Brooks said. “But most of the benefit to a mask is to block particles coming out of people who don’t know they are infected from exposing others.”

Masks create a barrier that stops some of the droplets from flying outward when someone breathes, talks, sings or coughs. A study released last week showed that, in experimental conditions, simple fabric masks blocked about threefourths of the particles expelled by coughing volunteers.

But it was a logical hypothesis for researchers to investigate, too, whether masks might also block incoming particles. And laboratory tests in recent months indicated that masks can filter out the types of incoming particles able to carry virus, Brooks said.

The CDC official added that personal protection for the mask-wearer is not absolute.

“The real benefit is when all of us do it, that’s how we bring down the viral load of COVID-19 incommunities,” Brooks said.