Annenberg Public Policy Center of the University of Pennsylvania Sep 13 2025 Although Health and Human Services Secretary Robert F. Kennedy Jr. posted on social media in April that the "most effective way to prevent the spread of measles is the MMR vaccine," in a CBS News interview that month he said, "The federal government's position, my position, is that people should get the measles vaccine, but the government should not be mandating it." The Trump administration's Make America Healthy