SAN DIEGO -- As more parents question vaccine safety, the number of exemptions for school immunizations goes up.

"When we were growing up, the doctor said, 'Do this,' and you just did it, without question," said parent Robin Sirota. "And I think now we've become, as consumers, we've been more educated on the products that we're using."

California law allows parents to exempt children from one or more required immunizations based on personal beliefs. Over the past decade, the percentage of exempted kindergartners in San Diego County has more than doubled.

"The problem we're beginning to see as more parents choose not to have their children immunized is we're starting to see disease as a result of that," said Dr. Mark Sawyer of Rady Children’s Hospital and professor of clinical pediatrics at University of California at San Diego.

A child entering kindergarten in California is generally required to have a total of 29 doses of nine different vaccines: diphtheria, tetanus, pertussis, polio, hepatitis B, measles, mumps, rubella and chicken pox.

"I'm not against vaccines. I just like to go slower at it. Make sure the vaccine's well-tested and not give too many vaccines all at the same time," said Sirota.

Sirota filed personal belief exemptions for her sons because they had all vaccines except the one for chicken pox.

"That’s just from the research that I’ve done, what I understand and the path that I chose," she said.

In San Diego County, 1,011 kindergartners had exemptions on file in 2008.

The two traditional public schools with the highest percentage of kindergarten exemptions last year were both in Encinitas: Paul Ecke Central Elementary with 22 percent, and Flora Vista Elementary at 21 percent.

The private school in the county with the highest percentage of kindergarten exemptions was The Waldorf School of San Diego at 60 percent.

Parents of vaccinated children the I-Team spoke to reacted differently to these findings.

"I think if people want to go to public school, then they should vaccinate their kids," said a mother of a five-year-old.

"I really think it's important that they have their own choice, what they do with their own children," said another mother of two boys.

"Hopefully every parent is getting as educated as possible," said a father of three children.

Dr. Sawyer recommends that parents fully vaccinate their children.

"There’s no scientific evidence that vaccines are causing harm to children," he said. "For me, vaccines are the most important thing that we do in preventive health care."

Dr. Sawyer also explained that the more unvaccinated children and adults there are in a community, the more likely that disease outbreaks will occur. And with certain diseases, even those who are vaccinated are at risk.

"Both chicken pox and whooping cough are good examples of that. In round numbers, those vaccines prevent disease completely only in about 80-percent of those that are immunized. So the other 20 percent can get disease – usually it’s mild disease," he said.

Sawyer is also concerned about people who can’t be vaccinated or when it’s not effective – babies, people who have problems with their immune system, and the elderly.

"And the way to protect people like that is to protect everyone around them. And if we get them immunized, then hopefully they won't get exposed," he said.

When parents sign a personal belief exemption, they are also agreeing that if an outbreak occurs, that student may have to stay home until it’s safe.