CDC: N95/KN95 masks most protective against COVID-19

LOS ANGELES, Calif. (KLKN) – A U.S. Center for Disease Control and Prevention (CDC) study found that consistently wearing a mask indoors, especially a KN95/N95 respirator, best protects against COVID-19.

In its Morbidity and Mortality Weekly Report, the CDC surveyed California residents to assess the effectiveness of different types of masks.

According to the study, consistent use of any face mask was protective.

However, the odds of infection were lowest among people who wore a N95/KN95 respirator, followed by wearing a surgical mask.

Wearing a cloth mask lowered a participant’s odds of infection by 56% compared to wearing no mask.

Those who used a surgical mask lowered their odds by 66%. Those who wore a N95/KN95 respirator did so by 83%.

Graph and data courtesy of the CDC

The research was conducted between Feb. 18 and Dec. 1, 2021, by the California Department of Public Health. It matched 652 people who tested positive for the coronavirus and with 1,176 participants who tested negative.

Researchers noted if the participants had been in indoor public places in the two weeks before testing, if they’d worn a mask, and for how long.

Surveyors also recorded vaccination status and and history of exposure. Participants enrolled between Sept. 9 and Dec. 1, 2021, were asked to indicate the type of face covering worn in public settings.

The CDC’s findings did not account for other preventative behaviors that may lower the risk of infection, such as social distancing.

Additionally, the CDC said the study was limited in its ability to account for the effectiveness of different face masks in various settings with different intensities of exposures. It was only able to look at the overall trends.

The data was collected before the Omicron variant, which is more infectious than earlier variants.

In addition to being up to date with the recommended COVID-19 vaccinations, the CDC recommends consistently wearing face masks or respirators in indoor, public settings to protect against infection.

Although a respirator offers the highest level of protection, the CDC says its most important to wear a well-fitting, comfortable mask that can be used regularly.