Effectiveness of Surgical and Cotton Masks in Blocking SARS–CoV-2: A Controlled Comparison in 4 Patients | Annals of Internal Medicine | American College of Physicians
Neither surgical nor cotton masks are effective at stopping the new coronavirus from spreading when a person coughs, a study suggests. The authors of the paper, published in the journal Annals of Internal Medicine, said more research is needed to determine whether such masks prevent the bug that causes COVID-19 from being passed on.