Americans Must Tighten Up, or Double Up, Their Masks, CDC Says

U.S. Centers for Disease Control and Prevention (CDC) officials are urging Americans to keep their masks on, and tighten them or wear two masks to reduce the spread of COVID-19, reports the New York Times . Lab experiments found that viral transmission could be slashed by 96.5 percent if Americans wore snug surgical masks or a combination of cloth and surgical masks. "The bottom line is this: masks work, and they work when they have a good fit and are worn correctly," said CDC Director Rochelle P. Walensky. Although masks reduce the respiratory droplets and aerosols exhaled by infected wearers and protect uninfected wearers, air leaking around the covering's edges can reduce its efficacy. To mitigate this, the CDC recommended wearing a cloth mask over a surgical mask, or fitting the surgical mask more tightly on the face by "knotting and tucking." Until most adults are immunized, "we want to tamp this down," said Vanderbilt University's William Schaffner, adding that masks can help avoid another catastrophic "roller coaster."