Evaluation of Cloth Masks and Modified Procedure Masks as Personal Protective Equipment for the Public During the COVID-19 Pandemic

This laboratory study found the fitted filtration efficiencies of seven types of consumer-grade masks and improvised face coverings varied from 26.5% to 79.0%. Modifications intended to enhance fit of medical masks improved measurements from 38.5% (unmodified) to up to 80.2%.

JAMA Internal Medicine