Scientists at the University of Copenhagen in Denmark have shown that a properly worn mask is probably not able to protect the wearer from contracting coronavirus. The difference in the risk of infection for a person with and without a mask, identified by specialists, is within the margin of error and is 20 percent. At the same time, scientists have not ruled out the real benefits of the widespread wearing of masks by potentially infected people. This is reported in an article published in the journal Annals of Internal Medicine.
About 6,000 people took part in a randomized controlled trial, with 3030 wearing masks depending on various recommendations, and 2994 people included in the control group in which masks were not worn. At the same time, everyone spent at least three hours outside the home, which, according to the recommendations, required wearing a mask.
Scientists checked how many volunteers will become infected with coronavirus in a month, which was determined by the results of antibody testing and PCR diagnostics. In addition, the level of infection with other respiratory viruses was detected.
Infection with SARS-CoV-2 was detected in 1.8 percent of people wearing masks and in 2.1 percent of participants in the control group. However, the researchers call the differences statistically insignificant, so they cannot rule out that the mask is not able to protect the wearer from infection if the people around him with COVID-19 do not wear masks themselves.
At the same time, the researchers did not assess how much a mask worn by an infected person reduces the likelihood of infection in other people. That is why, based on the results of scientific work, one cannot judge the lack of effectiveness of the widespread use of masks.