Surging COVID-19 rates throughout the country and in many parts of the world make our efforts to protect ourselves and others more important than ever. Yes, the predictions are dire, but we are not helpless. Experts estimate we can save hundreds of thousands of lives and considerably boost the chances of controlling the pandemic if we all commit to wearing a mask and follow familiar preventive measures: maintain physical distance; wash hands frequently; avoid others if you’re sick; and isolate yourself and get tested if you have close contact with someone who has the disease.
So, why do we believe masks work?
Early in the pandemic, experts expressed skepticism that masks would be helpful for the general public, particularly in places with little to no community spread of the virus. In addition, to avoid worsening shortages of medical-grade masks for health workers who needed this protection, masks were not widely recommended.
But we’ve seen a rapidly expanding body of evidence supporting the benefit of nonmedical masks and cloth face coverings. Some of the strongest evidence includes these reviews (here and here) and observational studies (here, here, here, and here), which found that mask-wearing leads to lower rates of infection. And this impressive graphic display from the New York Times shows how masks help trap larger respiratory droplets and some of the smaller particles known as aerosols.
No single study is perfect or definitive; in fact, such studies would be impossible to perform. But there is a lot going for mask-wearing, and little or no evidence that wearing a mask causes harm. So, if you’re a person who wants to avoid COVID-19, cares about the health of others, and endorses rational, evidence-based decision-making, choosing to wear a mask should be an easy call.