The results from mask wearing were “statistically insignificant” -- aka, masks dont do much if anything
"About 4,860 participants completed the study. 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."
“Our study gives an indication of how much you gain from wearing a mask,” said Dr. Henning Bundgaard, lead author of the study and a cardiologist at the University of Copenhagen. “Not a lot.”
Dr. Mette Kalager, a researcher at Telemark Hospital in Norway and the Harvard School of Public Health, was persuaded. The study showed that “although there might be a symbolic effect,” she wrote in an email, “the effect of wearing a mask does not substantially reduce risk” for wearers.
ACP Journals