STORY AT-A-GLANCE
- The first randomized controlled trial of more than 6,000 individuals to assess the effectiveness of surgical face masks against SARS-CoV-2 infection found masks did not statistically significantly reduce the incidence of infection
- Among mask wearers, 1.8% ended up testing positive for SARS-CoV-2, compared to 2.1% among controls. When they removed the people who did not adhere to proper mask use, the results remained the same — 1.8%, which suggests adherence makes no significant difference
- Among those who reported wearing their face mask “exactly as instructed,” 2% tested positive for SARS-CoV-2 compared to 2.1% of the controls
- 1.4% tested positive for antibodies at the end of the month-long study compared to 1.8% of controls
- 0.5% in the mask group and 0.6% tested positive for one or more respiratory viruses other than SARS-CoV-2