WASHINGTON (AP) — Amid the measles outbreak stemming from California, the White House is telling parents that science indicates they should vaccinate their children.

President Barack Obama’s spokesman, Josh Earnest, said Friday that decisions about vaccinations should be left to parents, but the science on vaccinations “is really clear.” Some parents continue to believe debunked research linking vaccines to autism and refuse vaccinate their children.

“I’m not going stand up here and dispense medical advice,” Earnest said when asked whether the president supports parents who choose not to vaccinate. “But I am going to suggest that the president’s view is that people should evaluate this for themselves, with a bias toward good science and toward the advice of our public health professionals, who are trained to offer us exactly this kind of advice.”

About 100 cases of the measles have been reported in the U.S. since last month in the second-biggest outbreak in at least 15 years. Most have been traced directly or indirectly to Disneyland in Southern California.

The Centers for Disease Control and Prevention says measles-mumps-rubella vaccine is 97 percent effective at preventing measles. The American Academy of Pediatrics says doctors should bring up the importance of vaccinations during visits but should respect a parent’s wishes unless there’s a significant risk to the child.