Mask Wearing Policy Did Not Prevent SARS-CoV-2 Infection in Community Setting Randomized Trial .

Global health agencies endorse masks as a key strategy to limit COVID-19 spread, particularly because roughly one in five infected individuals remain asymptomatic yet infectious. The only randomized trial to date—DANMASK-19—did not detect a statistically significant reduction in SARS-CoV-2 infection among individuals advised to wear surgical masks, but substantial limitations likely underestimated any benefit, including possible inclusion of asymptomatic cases at baseline, reliance on self-reported adherence, and unmeasured household transmission. In contrast, multiple observational and epidemiological studies consistently show reduced infection rates in settings with mask mandates or universal masking. Taken together, current evidence supports community masking, while DANMASK-19 remains inconclusive rather than disproving mask effectiveness.