Another study shows that wearing a mask lowers the odds of getting Covid-19, and that the type of mask you wear matters

Centers for Disease Control and Prevention chart

By Melissa Patrick
Kentucky Health News

Two years into the pandemic, many people still refuse to wear a face mask as part of a holistic approach to slow the spread of a virus that has killed more than 13,000 Kentuckians, despite public-health officials begging them to do so – and a wealth of research that supports their pleas. 

On Friday, another such study was released by the Centers for Disease Control and Prevention, showing real-world evidence that masks work, and that the type of masks you wear matters. 

“In addition to being up to date with recommended Covid-19 vaccinations, consistently wearing a comfortable, well-fitting face mask or respirator in indoor public settings protects against acquisition of [Covid-19] infection; a respirator offers the most protection,” says the early release report. 

The researchers said their study has limitations, but the results are consistent with previous research showing that masks prevent the spread of the virus.

The study assessed face-mask or respirator use among 652 people who tested positive for the virus and 1,176 who tested negative from Feb. 18 to Dec. 1, 2021 and self-reported being in indoor public settings during the two weeks preceding their test, with no known contact with any confirmed or suspected Covid-19 infection. The samples were randomly selected residents of California.

The study concluded, "Always using a face mask or respirator in indoor public settings was associated with lower adjusted odds of a positive test result, compared with never wearing a face mask or respirator in these settings."

Among the 534 study participants who reported the type of mask they used, cloth masks offered 56% more protection against the virus than wearing no mask indoors; surgical masks offered 66% more; and respirator mask, such as N95 or KN95, offered the most additional protection, 83%. 

"These data from real-world settings reinforce the importance of consistently wearing face masks or respirators to reduce the risk of acquisition of infection among the general public in indoor community settings," the report says. 

CDC guidance says that N95 masks, when they fit well and are worn correctly, provide the highest level of protection, while also maintaining that "any mask is better than no mask." Last month, the federal government began distributing 400 million free N95 masks through pharmacies and community health centers. 

State officials have long urged Kentuckians to wear masks in indoor spaces and especially in schools, but in September the legislature took away Gov. Andy Behsear's power to impose mask mandates.

A Kaiser Family Foundation survey taken mid-January found that most American adults (54%) say they wear a mask every time in an indoor, crowded space. The rate was highest among among vaccinated people (62%; unvaccinated 28%). It was also higher among Democrats (77%), followed by independents (50%) and Republicans (31%).