Unless their parents opt for a medical or religious exemption, young school children in New York City will soon be required to get a flu shot in order to attend preschool or gain access to a child care facility. As outlined by the New York City Health Department , children aged 6-59 months will be barred from attending classes or being around other children in an institutional setting if they don't first get jabbed for the flu -- this, despite warnings by the U.S. Centers for Disease Control and Prevention that this year's flu shot doesn't even work.