The US Senate confirmed Robert F. Kennedy Jr on Thursday to serve as the head of the Department of Health and Human Services (HHS).
President Donald Trump's pick was confirmed in a 52-48 vote.
Republican Sen. Mitch McConnell voted against Kennedy.
Kennedy faced criticism for his controversial stances on vaccines and public health policies.
During his confirmation hearing last month, Kennedy pledged to put the health of Americans "back on track."
Kennedy said he was not "anti-vaccine" when a protester shouted, "He lies!"
"I want to make sure the committee is clear about a few things. News reports have claimed that I am anti-vaccine or anti-industry. Well, I am neither; I am pro-safety," said Kennedy.
Sen. Ron Wyden tried to pin down Kennedy on his statements on vaccines. "Are you lying to Congress today when you say you are pro-vaccine or did you lie on all those podcasts?" he asked.
"I support the measles vaccine. I support the polio vaccine. I will do nothing as HHS secretary that makes it difficult or discourages people from taking either of those vaccines," Kennedy said.
Separately, Kennedy said he believes every abortion is a "tragedy," adding that states should control abortion.
