Volunteers help guide people to Covid-19 vaccination areas at the Fairfax Government Center vaccination clinic in Fairfax, Virginia on May 13, 2021. - The campaign to immunize America's 17 million adolescents aged 12-to-15 kicked off in full force on May 13, a key part of President Joe Biden's strategy to push the country close to herd immunity. (Photo by ANDREW CABALLERO-REYNOLDS / AFP)