An N95 Is the Best Mask for Omicron. Here's Why

As health officials scramble to minimize spread of the highly contagious Omicron variant, many experts have recommended that people switch from cloth or surgical masks to more-protective N95 and KN95 masks.The U.S. Centers for Disease Control and Prevention’s (CDC) current mask guidance does not recommend one type of mask over another, instead specifying that people should wear a mask that fits snugly and covers the nose and mouth. Then, in April 2020, the CDC changed its guidance to recommend masks—but specifically asked people to wear cloth face coverings rather than medical masks to reserve inventory for health care workers.Supply has stabilized since then, yet many Americans continue to wear either cloth or flimsier surgical masks instead of N95 or KN95 respirators. Cloth masks act as a physical barrier but typically provide even less filtration than surgical masks.With its high transmissibility, “Omicron has really changed how we need to protect ourselves against getting this,” says Dr. Mohammad Sobhanie, an infectious disease physician at the Ohio State University Wexner Medical Center. A similarly designed study published in 2020 found that N95 and KF94 masks were even better at containing droplets and aerosols than surgical masks.Wearing “anything is worth it,” says Kareem Ahmed, an associate professor of mechanical and aerospace engineering at the University of Central Florida and co-author of the new study.