Shots will be administered on Thursdays from 9 a.m. to 1 p.m. starting July 15 at the West Side high school. Students, their relatives and community members may register in advance, and walk-ins are also being accepted for the free vaccines. The two-dose Pfizer vaccine is the only one currently approved for individuals ages 12 to 17. A parent or guardian is required to be present for anyone under 18. Students 18 and older are also eligible for the single-dose Johnson & Johnson vaccine.