Areas of Tennessee where residents regularly wear masks in public have seen notably smaller increases in COVID-19 hospitalizations since June, researchers at the Vanderbilt University School of Medicine found.
Just over half of Tennesseans, 54%, live in a county that has a mask ordinance in place. Researchers classified hospitals based on the percentage of patients they treat that reside in counties with a mask requirement.
"Hospitals that predominantly serve patients from areas without masking requirements (the <25% group) continue to see the highest rate of growth in hospitalizations," researchers wrote.
Wearing a mask is not a "silver bullet" though, as every area of the state has seen an increase in hospitalizations, but the growth "has been most dramatic in hospitals that draw a large percentage of patients from areas without mask requirements."
It may not just be masks that are slowing the spread, as areas with a mask requirement are also more likely to have other mitigation strategies in place.
The study from Vanderbilt University is the latest research to show that masks are an effective tool in mitigating the spread of coronavirus.
According to the University of Washington's Institute for Health Metrics and Evaluation, which tracks and forecasts COVID-19 cases, "mask use results in up to 50% reduction in transmission of COVID-19."
Anecdotal evidence also shows that masks are effective. For instance, two hairstylists in Missouri saw 140 clients earlier this summer while infected with COVID-19, but none of the clients ended up contracting the disease, which health officials attributed to the workers wearing masks.
The CDC recommends that people wear masks in public settings, but masks have turned into a political flashpoint during the pandemic.
President Trump resisted masks for months, but has since encouraged Americans to wear them, saying in August that it "is a patriotic thing to do."
Democratic presidential candidate Joe Biden, meanwhile, has called for nationwide mask-wearing compliance, saying two months ago that "every single American should be wearing a mask when they’re outside for the next three months at a minimum."