Long before the COVID-19 pandemic, Robert F. Kennedy Jr. was building up a following with his anti-vaccine nonprofit group, Children’s Health Defense, and became one of the world’s most influential spreaders of fear and distrust around vaccines.

Colorado Gov. Jared Polis said he was “excited” for Kennedy to lead HHS. Polis said he wants to see Kennedy take on “big pharma” and hopes he will “lean into personal choice” on vaccines.

The nearly $2 trillion agency administers health-insurance programs for millions of Americans, approves medications and oversees vaccine safety.