Mask mandates may have prevented hundreds of thousands of coronavirus cases

Some states' requirements that face masks be worn in public may have led to hundreds of thousands of fewer coronavirus cases than there would have been without the mandates, according to a new study in Health Affairs.

Yes, but: Despite the growing body of evidence that this simple mitigation strategy is one of our best defenses against the coronavirus, wearing them remains controversial, and mandating their use even more so.

Between the lines: When everyone wears a face mask, it helps reduce spread of the virus by all carriers — including those who are asymptomatic and pre-symptomatic.

• The study found a "significant decline in daily COVID-19 growth rate after mandating facial covers in public, with the effect increasing over time after signing the order."
• Although only 15 states plus the District of Columbia required mask use in public, between 230,000 and 450,000 coronavirus cases may have been averted by May 22.
• 20 other states have more limited mask requirements, but "results indicate no evidence of declines in daily COVID-19 growth rates with the employee-only mandates," the authors write.

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