Hillary Clinton’s vaccine views have changed since 2008.  (Carolyn Kaster/AP)

With the vaccination debate spreading into the GOP presidential race, Hillary Rodham Clinton jumped into the fray by taking a swipe at some of her prospective Republican opponents.

“The science is clear: The earth is round, the sky is blue, and #vaccineswork,” Clinton wrote on Twitter. “Let’s protect all our kids. #GrandmothersKnowBest”

Clinton made her remarks on Monday night, hours after New Jersey Gov. Chris Christie (R) and Kentucky Sen. Rand Paul (R) went in the other direction by giving credence to the fears of people opposed to vaccinating children.

Christie called for “some measure of choice” in the matter, and Paul said that he thinks most vaccines should be voluntary, citing “many tragic cases of walking, talking, normal children who wound up with profound mental disorders after vaccines.”

An outbreak of measles that has now spread to 14 states began after an unvaccinated family visited Disneyland in California. The outbreak — years after the disease was effectively eliminated — has revived a debate about whether public health officials are losing to “anti-vaxxers” when it comes to the well-established science supporting both the safety and efficacy of the measles vaccination.

However, while running for president in 2008, Clinton appeared to have held different beliefs on the now-discredited claims that vaccines cause autism. Asked in a questionnaire by an autism group whether she would support investigating vaccines as a possible cause of autism, Clinton said that she would.

“I am committed to make investments to find the causes of autism, including possible environmental causes like vaccines,” Clinton wrote.

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