Fewer California parents opted out of vaccinations for their children entering kindergarten last year following the adoption of a law that makes it harder to go without the shots, state figures show.

The issue has taken new prominence as California deals with an outbreak of measles that originated at Disneyland last month, sickening 78 people. Most of the infections are in California and most of those who got sick were unvaccinated. Measles has also been confirmed in six other states — Utah, Washington, Colorado, Oregon, Nebraska and Arizona — and Mexico.

The rate of personal-belief exemptions for kindergartners fell from 3.1 percent in 2013 to 2.5 percent last year, according to data collected by the California Department of Public Health. It's the first drop after years of record number of parents seeking waivers to avoid school immunization requirements.

"The early signs look good. However, it is too early to make a definitive determination. We will have to make sure that this trend is stable," Saad Omer, an associate professor of global health at Emory University, said in an email.

California is among 20 states that allow parents to forgo vaccines for their children because of personal beliefs. Under the immunization law that took effect last year, parents claiming a personal-belief exemption from vaccines must have a signed form from their doctor saying that they have received information about the risks of opting out. Gov. Jerry Brown added a last-minute religious exemption that does not require a doctor's signature. Previously, parents were not required to supply any information to explain their decision.

The drop in vaccine exemptions was also seen in school districts with traditionally high numbers of unvaccinated kindergartners.

In the Santa Monica-Malibu Unified School District, the rate declined from 14.8 percent to 11.5 percent. In Capistrano Unified in south Orange County, the rate fell from 9.5 percent to 8.6 percent, according to an analysis published Friday by the Los Angeles Times (http://lat.ms/1Cm8LYJ).

Public health officials have worried about the re-emergence of vaccine-preventable diseases like measles and whooping cough due to unimmunized populations.

In the latest measles outbreak, most of those who got sick had not gotten the measles-mumps-rubella, or MMR, vaccine. While measles has been eliminated in the U.S. since 2000, the virus can still enter the country from abroad where it's still a problem.

Public health officials have redoubled their efforts urging people to get their measles shots.