Wearing face masks in public prevented as many as 450,000 new cases of COVID-19, according to a new study. That study, published online in the journal Health Affairs, estimates between 230,000 and 450,000 cases of the virus were prevented in the states that enacted requirements for mask use between April 8 and May 15.
Researchers say wearing face masks in public reduced the daily number of coronavirus cases by as much as two percent in Washington D.C. and the 15 states that required their use, compared to the states that did not. The longer the mandates were in place, the higher the reduction in COVID-19 cases.
Researchers also looked at 20 states that imposed employee-only mandates but not public mask use and did not find a significant impact on the spread of the coronavirus in those states.
The study did have some limitations, including the inability to measure the actual use of face coverings in any community, and researchers were only able to measure confirmed cases of COVID-19 despite evidence that infection rates in some communities were higher.
In April, the CDC issued new guidelines encourage cloth face coverings in public places where social distancing measures are hard to maintain.