Vitamin A & a good stern back-of-the- legs switching will protect your kids from measles, says HHS Chief RFK Jr. “A nice long, thin flexible willow branch applied with loving yet forceful strokes against the back of your kids’ bare legs will go far in keeping them from contracting measles, RFK Jr said. He recommends that parents use a smooth application of Vitamin A cream on the back of their children’s little legs before switching.