Socially distanced kindergarten students wait for their parents to pick them up on the first day of in-person learning at Maurice Sendak Elementary School on April 13, 2021, in Los Angeles. Vaccination rates for U.S. kindergarteners in 2022 saw a significant drop for the second year in a row, according to new data released Thursday, Jan. 12, 2023, and worried federal officials are launching a new campaign to try to help bring them back up. (AP Photo/Jae C. Hong, File)