On Monday, the Centers for Disease Control and Prevention (CDC) updated its issued guidelines on masks. Given data from recently conducted experiments, the guidance now indicates that having a cloth over a surgical mask was proven to be effective in limiting the spread of COVID-19. The same goes for using a mask that fits properly.
CDC Guidelines Update: Layering Masks Work
The agency’s director, Dr. Rochelle Walensky, announced the update at a White House COVID-19 briefing. It comes after recent experiments using simulation found that a cloth mask over a surgical mask can decrease a person’s exposure to infectious aerosols by 95%.
For it to be effective, the masks need to have knotted ear bands and tucked sides. The guidance also suggests making sure the masks fit well against the face and using masks with layers. The CDC also suggests using masks that have a nose wire or using a mask fitter to improve fit.
With this, however, the CDC advises against the use of two disposable masks. According to the agency, such masks are “not designed to fit tightly” and that layering them would not improve the fit of the masks. It also advises against layering a KN95 mask with other types of masks.
Walensky then reiterated that “masks work” and that they are most effective when they “have a good fit and are worn correctly.
A few weeks ago, the CDC revealed that it was conducting research on whether two masks were effective in limiting COVID-19 spread. It came after infectious disease expert Dr. Anthony Fauci said that the idea “makes common sense.”
According to the agency’s chief medical officer, Dr. John Brooks, the CDC had since been holding off until they could have “hard data” before adjusting their guidelines.