Washington Post – “…urging double masks in some cases CDC also found that improving the fit of a single surgical mask boosted protection from potentially infectious aerosols. Federal health officials on Wednesday urged Americans to consider wearing two masks as one of several strategies to better protect themselves against the threat of more contagious variants of the coronavirus. “We know that universal masking works,” said John T. Brooks, medical officer for the Centers for Disease Control and Prevention’s covid-19 response. “And now these variants are circulating … whatever we can do to improve the fit of a mask to make it work better, the faster we can end this pandemic.” Two methods substantially boost fit and protection, according to a CDC report and guidance released Wednesday. One is wearing a cloth mask over a disposable surgical mask. The second is improving the fit of a single surgical mask by knotting the ear loops and tucking in the sides close to the face to prevent air from leaking out around the edges and to form a closer fit. Both of those methods reduced exposure to potentially infectious aerosols by more than 95 percent in a laboratory experiment using dummies, the report said…”

• Source – CDC Guide to Masks – “CDC recommends that people wear masks in public settings, at events and gatherings, and anywhere they will be around other people. Effective February 2, 2021, masks are required on planes, buses, trains, and other forms of public transportation traveling into, within, or out of the United States and in U.S. transportation hubs such as airports and stations…”
• Source – CDC – Maximizing Fit for Cloth and Medical Procedure Masks to Improve Performance and Reduce SARS-CoV-2 Transmission and Exposure, 2021