by: Aaron Pero Posted: May 27, 2021 / 02:09 PM PDT / Updated: May 27, 2021 / 02:09 PM PDT Simon Huizar, 13, receives a first dose of the Pfizer Covid-19 vaccine at a mobile vaccination clinic at the Weingart East Los Angeles YMCA on May 14, 2021 in Los Angeles, California. – The campaign to immunize America’s 17 million adolescents aged 12-to-15 kicked off in full force on May 13.