Robert F. Kennedy Jr.'s record of questioning childhood vaccine safety came under fire from a key Republican at the Trump HHS pick's confirmation hearing.

Robert F. Kennedy Jr., a former presidential candidate and environmental activist, endorsed Donald Trump last year and threw his weight behind a campaign to “Make America Healthy Again.” For the past two decades he has been best known for airing skeptical views on vaccines.

In a contentious confirmation hearing to become the nation’s top health official, Robert F. Kennedy Jr. struggled Wednesday to answer questions about Medicare and Medicaid, programs that affect tens of millions of Americans,

If approved, Kennedy will control a $1.7 trillion agency that oversees food and hospital inspections, hundreds of health clinics, vaccine recommendations and health insurance for roughly half the country.

RFK Jr. claimed he is not “anti-vaccine” and appeared unfamiliar with key aspects of healthcare insurance programs in his confirmation hearing.

Robert F. Kennedy Jr. was confronted with a number of his baseless claims and a vexing abortion issue. But Republican senators treaded lightly.

During his confirmation hearing for health secretary on Jan. 29, Robert F. Kennedy Jr. called the Make America Healthy Again agenda one of the most "powerful movements I’ve ever seen.”

Robert F. Kennedy Jr’s confirmation hearings began Wednesday before the Senate Finance Committee. He appears before the Health, Education, Labor and Pension committee on Thursday.

Robert F. Kennedy Jr., Tulsi Gabbard and Kash Patel are each set to appear before lawmakers during a pivotal day of confirmation hearings Thursday.

Robert F. Kennedy Jr. has said vaccines are not safe. His support for abortion access has made conservatives uncomfortable.

If confirmed by the Senate, Kennedy would head the Department of Health and Human Services (HHS), which oversees many of the country’s health agencies, from the Food and Drug Administration (FDA) to the Centers for Disease Control and Prevention (CDC).

What to know from Robert F. Kennedy, Jr.’s hearings before the Senate Finance Committee on Wednesday and the Senate Health, Education, Labor, and Pensions on Thursday.