More than nine in 10 Americans live in a county where COVID-19 risk is so low that they don’t need to wear a mask, according to a U.S. health agency. The Centers for Disease Control and Prevention (CDC) on March 3 updated its community COVID-19 map, which estimates risk by county based on COVID-19 infections, hospital admissions, and hospitalized patients. Over 90 percent of the U.S. population lives in a county where the risk is designated low or medium, meaning masks should not be required, according to the CDC. Some states have no counties labeled high risk, including Nevada, Maine, and South Carolina. A handful have large areas designated high risk, including Nebraska, Kentucky, and West Virginia. The map will be updated every Thursday moving forward, a CDC spokesperson said. Before Feb. 25, the CDC recommended mask-wearing for over 95 percent of the country. On that day, the agency drastically …