Masks Have Helped To Blunt the COVID-19 Pandemic in Kansas

While masks are not a panacea for controlling the COVID-19 pandemic, there is mounting evidence that they are a useful tool for slowing community transmission of the disease. Researchers at the Centers for Disease Control and Prevention (CDC) took advantage of a natural experiment in Kansas, producing an analysis of mask efficacy after some counties enacted a mask mandate and others did not.

On July 2, Kansas Gov. Laura Kelly issued an executive order requiring people to wear face coverings when entering any indoor public space, visiting health care facilities, or using public transportation. State law, however, authorizes counties to issue public health orders that are less stringent than statewide executive orders. Many counties opted out of Kelly’s mask mandate.

During the period of the CDC study, 24 counties adopted a mask mandate whereas 81 counties did not. The researchers then compared what happened to the COVID-19 incidence trends in counties with and without mandates. They reported that in early June, a month before Kelly’s order, the daily average COVID-19 incidence rate in counties that would eventually adopt a mask mandate was three cases per 100,000. In counties that ultimately chose not to mandate masks