Kyra Kennedy, 29, is the youngest daughter of health secretary nominee Robert F. Kennedy Jr.

Robert F. Kennedy Jr.'s long record of questioning the safety of childhood vaccinations persisted as a flash point for him Thursday during a confirmation hearing where a key Republican quickly raised concerns about his views.

The hearings were packed to capacity with protesters and fans, while the spillover crowd hung out in hallways and overflow rooms.

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.

Robert F. Kennedy Jr. will stand before the Senate Finance Committee on Wednesday and the Senate Health, Education, Labor and Pension Committee Thursday as President Donald Trump's nominee to lead the Department of Health and Human Services.

Caroline Kennedy, daughter of former President John F. Kennedy, warned senators of her “predator” cousin ahead of his first confirmation hearing on Wednesday. In a letter first reported by The Washington Post, she wrote that his victims included family members and parents of sick children.

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.

Robert F. Kennedy Jr., President Trump's pick for Secretary of Health and Human Services, explained to Sen. Ron Johnson (R-WI) how he would approach administering the department. ROBERT F. KENNEDY JR.

Robert F. Kennedy Jr. will face the Senate for two days of confirmation hearings in a bid become the leader of Health and Human Services.

Kennedy's condition is called spasmodic dysphonia, which is a neurologic disorder that can affect the voice and speech by causing the muscles that generate a person’s voice to go into periods of spasm, according to Penn Medicine. It is a lifelong condition, but can be improved with treatment in some cases, according to Penn Medicine.

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

Attacks on scientific expertise have been increasing, especially in politics. Health and Human Services nominee Robert F. Kennedy Jr. is among the more prominent people who have done that.