A California law that took effect last year is making it harder for parents to opt out of vaccinating their children.
State figures show personal beliefs exemptions for kindergarteners dropped from 3.1 percent in 2013 to 2.5 percent last year.
A Los Angeles Times (http://lat.ms/1Cm8LYJ ) analysis found the rate also fell in school districts with high numbers of unvaccinated kindergarteners.
The law requires parents claiming a personal belief exemption from vaccines to have a signed form from their doctor.
Public health officials have worried about the re-emergence of vaccine-preventable diseases like measles and whooping cough due to unimmunized schoolchildren.
A measles outbreak that originated in Disneyland last month has sickened six dozen, mostly unvaccinated, people in six states and Mexico with the majority of infections in California.