AUSTIN, Texas (AP) – Texas could host the nation’s next major fight over stricter requirements for immunizations as its rates of schoolchildren who refuse to get shots for non-medical reasons rises.

The number of Texas kindergarten through 12th grade students who reported filing conscientious exemptions for at least one immunization last school year increased 19-fold since 2003. It’s still less than 1 percent of enrolled students.

Texas and 17 states allow philosophical exemptions to vaccines. California used to allow many students to forgo vaccinations, only to approve some of the country’s strictest vaccine requirements last year.

In Texas, some state lawmakers said Wednesday that they want to create a system where students who object to immunizations would have to opt out. Currently, Texas makes parents “opt in” by approving vaccines.