June 19, 2020 – We ran a meta-analysis on more than 20 studies on mask use. Our results show that masks, whether cloth or medical-grade, can reduce the risk of respiratory illnesses like COVID-19 by 1/3 or more.

Widespread mask use may temper or even help prevent a second wave of the pandemic, though survey data show mask use varies worldwide. It is increasingly important that we wear masks anytime we’re in public and encourage others to do the same.