In a 2014 study published by the National Library of Medicine – National Center for Biotechnology Information, when tested against an influenza-infused aerosol from a distance of 18 inches away, a face shield reduced exposure by 96% during the period immediately after a cough. A face shield also reduced the surface contamination of a respirator by 97%. With similarities between influenza and COVID-19, these are some promising numbers. Because COVID-19 is a new virus, public health professionals are still learning more about its transmission, symptoms, and severity. CDC is staying very cautious with regards to recommendations about what face coverings work best. More research is necessary to make final conclusions.
Dr. Frank Esper from Cleveland Clinic says “Because face shields extend down from the forehead, they protect the eyes as well as the nose and mouth.” Dr. Esper is a pediatric infectious disease specialist at the clinic. The coverage that face shields offers is ideal since the new coronavirus can enter the body through those points the same as influenza. “It protects the wearer,” Dr. Esper adds. “But if you cough, because the face shield is away from your face, those droplets can still get out better than if you have a mask on.” CDC does not recommend wearing face shields for normal everyday activities or as a substitute for cloth face coverings. However, some people may choose to use a face shield when they know that they’ll be in sustained close contact with others like in school classrooms, restaurants, or at the barbershop. Another thing to note is that masks absorb droplets when we sneeze or cough. Face shields don’t as they do not have a porous surface. Dr. Esper stresses that, should you decide to wear a face shield, you’ll need to sanitize it frequently.