Fox News host Megyn Kelly late Monday said she supports mandatory vaccinations, an issue that has become increasingly political, after more than 100 cases of measles have been reported in the U.S.

Appearing on "The O'Reilly Factor," Kelly said she feels there is sufficient scientific evidence to prove vaccines are effective. She added that she vaccinated all of her children, as recommended by their doctor.

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"Five years ago, the science wasn't even as certain as it is today," she said. "But it is very certain today."

The issue of whether parents should have the choice to vaccinate their children has caused a political stir among potential GOP 2016 presidential candidates.

New Jersey Gov. Chris Christie and Kentucky Sen. Rand Paul on Monday both said parents should have the freedom to make their own decision. Others, like retired neurosurgeon Ben Carson, stressed that public health and safety should be a priority.

Kelly said those who argue that parents should have a choice were given "bad information" from a study in the 1990s that linked vaccinations to mental health complications.

But now that there is scientific support, it's time for the government to step in and protect public health, she said.

"This is going to be a big political issue for politicians going forward, because it's about Big Brother," Kelly added. "But on the other hand, some things do require some involvement of Big Brother."

— Jonathan Easley contributed to this report.