Robert F. Kennedy Jr.

Already controversial because of his skepticism about vaccines, Robert F. Kennedy Jr. has proven a lightning rod since he was sworn in as secretary of the U.S. Department of Health and Human Services (HHS) on Feb. 13. Pledging to “Make America Healthy Again,” he is overseeing a massive reorganization of HHS that includes downsizing its head count from 82,000 to 62,000 and slashing billions in grants that fund medical research. As the CDC worked to contain a measles outbreak which has infected more than 700 and killed two young children and one adult—the first such deaths from the disease in the U.S. in years—Kennedy has both endorsed the measles, mumps and rubella vaccine and also claimed that it was “not safety tested,” despite decades of scientific consensus that the vaccine is safe and effective. Kennedy’s statements about vaccines while in office have alarmed many in public health. And after a new CDC study showed a rising incidence of autism among children, Kennedy called the increase an “epidemic,” infuriating many scientists who say that the rise is driven by increased awareness and screening; he vowed new studies on environmental toxins, which he says have sent autism rates soaring, dismissing scientific evidence on other factors that can contribute to the disorder, like genetics. Kennedy is also moving quickly on some of his other top causes, pushing food manufacturers to phase out petroleum-based food dyes and trying to close a loophole that has allowed new ingredients to get into food uninspected—winning new allies, and critics, along the way.