Few issues are more contentious in modern American life than mandatory mask orders. And the debate is about to get even more heated.
A newly released study in the academic journal Annals of Internal Medicine casts more doubt on policies that force healthy individuals to wear face coverings in hopes of limiting the spread of COVID-19.
“Researchers in Denmark reported on Wednesday that surgical masks did not protect the wearers against infection with the coronavirus in a large randomized clinical trial,” the New York Times reports.
The study is perhaps the best scientific evidence to date on the efficacy of masks.
To conduct the study, which ran from early April to early June, scientists at the University of Copenhagen recruited more than 6,000 participants who had tested negative for COVID-19 immediately prior to the experiment.
Half the participants were given surgical masks and instructed to wear them outside the home; the other half were instructed to not wear a mask outside the home.
Roughly 4,860 participants finished the experiment, the Times reports. The results were not encouraging.
“The researchers had hoped that masks would cut the infection rate by half among wearers. Instead, 42 people in the mask group, or 1.8 percent, got infected, compared with 53 in the unmasked group, or 2.1 percent. The difference was not statistically significant,” the Times reports.
Dr. Henning Bundgaard, lead author of the experiment and a physician at the University of Copenhagen, told the newspaper the results of his research are clear.
“Our study gives an indication of how much you gain from wearing a mask,” Bundgaard said. “Not a lot.”
The Times notes that the research “did not contradict growing evidence that masks can prevent transmission of the virus from wearer to others”—but adds that the study’s findings are at odds with the Centers for Disease Control and Prevention (CDC), which just last week endorsed the view that face coverings protect individuals from contracting the virus.