New Jersey Gov. Chris Christie (R) said Monday that public officials need to strike a “balance” on vaccinations that allows parents “some measure of choice” in immunizing their children.

Christie was asked about a measles outbreak afflicting the western U.S. during a visit to a facility for MedImmune, an American company that manufactures a flu vaccine. The visit was part of the governor’s three-day trip to London.

Asked about the outbreak’s link to parents who object to the measles vaccine, Christie said that he and his wife chose to vaccinate his four children, according to the New York Times.

“It’s more important what you think as a parent than what you think as a public official,” Christie said, as quoted by the Times. “I also understand that parents need to have some measure of choice in things as well. So that’s the balance that the government has to decide.”

In response to the outbreak, President Barack Obama urged parents to vaccinate their children during a pre-Super Bowl interview on Sunday.

“I understand that there are families that, in some cases, are concerned about the effect of vaccinations,” he said. “The science is, you know, pretty indisputable. We’ve looked at this again and again. There is every reason to get vaccinated, but there aren’t reasons to not.”

By contrast, Christie said Monday that “not every vaccine is created equal, and not every disease type is as great a public health threat as others,” according to the Times.

During the height of the U.S. Ebola scare in October, Christie deemed the virus a strong enough threat to public health to warrant mandatory quarantines for all health workers returning to New Jersey from treating Ebola patients in West Africa.