1; Donald H. Beezhold, PhD2; John D. Noti, PhD2; Jayme P. Coyle, PhD2; Raymond C. Derk, MS2; Francoise M. Blachere, MS2; William G.
Lindsley, PhD2 (View author affiliations)Universal masking is recommended to slow the spread of COVID-19. Cloth masks and medical procedure masks substantially reduce exposure from infected wearers (source control) and reduce exposure of uninfected wearers (wearer exposure).
CDC conducted experiments to assess two ways of improving the fit of medical procedure masks: fitting a cloth mask over a medical procedure mask, and knotting the ear loops of a medical procedure mask and then tucking in and flattening the extra material close to the face.