Rand Paul Says Vaccines Can Lead to 'Mental Disorders' The Kentucky senator says parents should make vaccination decisions.

 -- In a contentious interview today, Sen. Rand Paul said he's heard of cases where vaccines lead to “mental disorders” and argued that parents should be the ones to choose whether they vaccinate their children, not the government. Paul is a former ophthalmologist.

“I’ve heard of many tragic cases of walking, talking normal children who wound up with profound mental disorders after vaccines,” Paul, R-Ky., said in an interview with CNBC anchor Kelly Evans.

“I’m not arguing vaccines are a bad idea. I think they’re a good thing, but I think the parents should have some input," he added. "The state doesn’t own your children. Parents own the children and it is an issue of freedom.”

Earlier in the day, Paul told Laura Ingraham that most vaccines “ought to be voluntary.”

Vaccinations have emerged as a political topic this week after President Obama urged Americans to vaccinate their children amid a measles outbreak.

"You should get your kids vaccinated,” the president said in an interview with NBC on Sunday.

In London today, New Jersey Gov. Chris Christie offered an opposing view to the president's, saying that families should have a “measure of choice” in whether they should vaccinate their children.

"There has to be a balance and it depends on what the vaccine is, what the disease type is, and all the rest," Christie said, according to the Washington Post. "Not every vaccine is created equal and not every disease type is as great a public health threat as others."

However, the American Academy of Pediatrics affirmed today the importance of vaccines along with their relatively low risk of harm. In a statement, the group stressed that the MMR vaccine for measles, mumps and rubella is one of the safest and most effective vaccines given, and strongly urged parents to stick to the vaccine schedule recommended by the U.S. Centers for Disease Control and Prevention.