Higher levels of COVID-19 vaccination in a population are tied to lower rates of infection in unvaccinated youth younger than 16 years, who were ineligible for the vaccine at the time of the trial, according to an observational, real-world, Israeli study today in Nature Medicine.Researchers from Technion-Israel Institute of Technology in Haifa led the study, which involved mining vaccination records and COVID-19 test results gathered during a rapid vaccine rollout in 177 communities.They found that vaccination rates in each community were linked to a large subsequent decline in COVID-19 infections in the unvaccinated youth.