Kennedy, a longtime vaccine critic who has pushed a discredited theory that routine childhood shots cause the developmental disability, said the effort will be completed by September and involve hundreds of scientists. He shared the plans with President Donald Trump during a televised Cabinet meeting.

Kennedy Jr. hiked to the top of a towering sandstone arch in rural Arizona with a group of Navajo Nation leaders, the impact of his agency’s cuts reached farther. Wearing a shirt with a clear request written on the front,

HHS administers health insurance programs that affect nearly half the U.S. population, including Medicare and Medicaid, and regulates medical products and food. Critics warn that the scale of the cuts could jeopardize disease response capacity, scientific research, and regulatory oversight.