The Biden administration estimates that 97% of Americans ages 16 and over have some level of COVID-19 immunity through vaccination, previous infection or both. The number may sound promising – so why do people need another round of shots? Because that protection can fade in a matter of months, leaving individuals vulnerable to COVID-19 once again. “Immunity is stronger today than at any other point in the outbreak,” Mandy Cohen, the director of the Centers for Disease Control and Prevention, said in a recent video statement. “That means we're moving towards COVID-19 being a more manageable illness with less severe...