Westchester County is offering free back-to-school vaccines today. All children who do not have their required immunizations must have the first dose of vaccines within 14 days from the first day of school. Today’s clinic will take place from 9 a.m. to 2 p.m. at 20 S. Broadway in Yonkers. Appointments can be made by calling the Westchester County Department of Health at 914-995-5800.