Nham La Man Nhi, 13, receives her Covid-19 vaccine administered by medical assistant Karina Cisneros from St. John's Well Child & Family Center at Abraham Lincoln High School in Los Angeles, California on May 13, 2021, on the first day of availability of the vaccine for the 12-15 year old age group. - 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 Frederic J. BROWN / AFP)