Medical Masks Versus N95 Respirators for Preventing COVID-19 Among Health Care Workers : A Randomized Trial.
Ann Intern Med. 2022 Dec;175(12):1629-1638. doi: 10.7326/M22-1966. Epub 2022 Nov 29.
Ann Intern Med. 2022.
PMID: 36442064
Free PMC article.
Clinical Trial.