Sen. Rand PaulRand PaulPaul: Pence should oversee Senate ObamaCare repeal votes Healthcare fight pits Trump against Club for Growth GOP rep: Trump could be 'one-term president' if healthcare bill passes MORE (R-Ky.) doubled down on his position that most vaccines should be voluntary, suggesting Monday that mandated immunization is an example of government overreach.
"The state doesn't own your children," Paul said in an interview with CNBC's "Closing Bell." "Parents own the children, and it is an issue of freedom and public health."
The remark made waves as a widening measles outbreak in 14 states stirs political debate over vaccination.
Gov. Chris Christie (R-N.J.) also weighed in, saying that parents should have a "choice" in the matter but that ultimately "there is no question kids should be vaccinated."
In a heated interview with CNBC host Kelly Evans, Paul expressed support for vaccination but bristled at the idea that it should be mandatory.
"I guess being for freedom would be really unusual," he said sarcastically at the start of the exchange.
Paul also acknowledged hearing about cases in which healthy kids were left with "profound mental disorders" after being vaccinated.
Vaccine critics frequently claim that there is a link between immunization and autism, though medical studies have discredited the idea.
"I'm not arguing vaccines are a bad idea," Paul said, noting that his children were vaccinated on the recommended staggered schedule. "I think they are a good thing, but I think the parent should have some input."
Paul added that vaccines have been voluntary for "most of our history … so I don't think I'm arguing for anything out of the ordinary."
The debate over vaccination is taking on political overtones as the Obama administration comes out strongly for immunizing kids.
In an interview with NBC News that aired Monday, President Obama said the science behind vaccines is "pretty indisputable" and that "there is every reason to get vaccinated, but there aren't reasons to not."
The Centers for Disease Control and Prevention is also urging parents to follow normal immunization standards, with agency director Tom Frieden arguing Monday that unvaccinated children can endanger others.