Wearing a mask – any mask – reduces the risk of infection with the coronavirus, but wearing a better-fitting surgical mask or placing a cloth mask over a surgical mask can greatly increase protection for the user and others, Diseases and Prevention reported on Wednesday.
New research by the agency shows that the transmission of the virus can be reduced by up to 96.5% if an infected individual and an uninfected individual wear tight-fitting surgical masks or a combination of cloth and surgical mask.
Dr. Rochelle P. Walensky, director of the CDC, announced the findings during the coronavirus briefing at the White House on Wednesday, and joined them in an appeal for Americans to wear “a tight-fitting mask” with two or more layers . President Biden challenged Americans to wear masks during the first 100 days of his presidency.
“With hospitalization and death cases still very high, now is not the time to reverse mask requirements,” she said, adding: “The main point is this: masks work and work when they have a good fit and are used correctly. “
Virus-related deaths, which resurfaced sharply in the United States in November and still remain high, appear to be steadily declining; new cases of viruses and hospitalizations began to fall last month. But the researchers warn that a more contagious variant of the virus found for the first time in Britain is doubling approximately every 10 days in the United States. The CDC warned last month that it could become the dominant variant in the country in March.
As of February 1, 14 states and the District of Columbia had implemented universal masking mandates; masking is now mandatory on federal properties and on domestic and international transport. But although masks are known to reduce respiratory droplets and aerosols exhaled by infected users and to protect the uninfected user, their effectiveness varies widely because of air leakage around the edges of the mask.
“Any mask is better than none,” said Dr. John Brooks, lead author of the new CDC study. “There is substantial and convincing data that wearing a mask reduces the spread and, in communities that adopt a mask, new infections decrease.”
But, he added, the new research shows how to increase protection. The agency’s new laboratory experiments are based on ideas presented by Linsey Marr, an aerosol transmission specialist at Virginia Tech, and Dr. Monica Gandhi, who studies infectious diseases at the University of California, San Francisco.
One option to reduce transmission is to use a cloth mask over a surgical mask, the agency said. The alternative is to adjust the surgical mask more firmly on the face by “knotting and folding” – that is, tying the two strands of the ear loops where they attach to the edge of the mask and then folding and flattening the extra tissue in the edge of the mask and folding it for a firmer seal.
Dr. Brooks warned that the new study was based on laboratory experiments, and it is unclear how these masking recommendations will work in the real world (the experiments used three-layer tissue and surgical masks). “But it is very clear evidence that the more we who wear masks and the better the mask fits, the more each of us benefits individually. “
Other effective options that improve fit include using a mask adjuster – a face contoured frame – over a mask, or wearing a transparent nylon mesh sleeve around the neck and pulled over a cloth or mask surgery, said the CDC.
Even with vaccines slowly being rolled out across the country, the emergence of new variants, which may respond differently to treatments or prevent the immune system to some degree, has led public health officials to emphasize that Americans should continue to take protective measures such as masking.