There is a small but growing number of parents in Texas choosing not to vaccinate their children, according to state data. Many of those students are attending schools in Austin.

It’s important to remember that Texas is one of 18 states in the country that allows non-medical exemptions to the vaccines required for school attendance. That means you don't have to have a medical or religious reason to stop your kids from getting vaccinated.

Among the diseases that vaccines protect against are hepatitis A and B, whooping cough, measles, mumps, and meningococcal.

"You want to see people protected from diseases that vaccines can prevent and if that's not happening, or it's not happening as frequently then it certainly increases the chances that someone will get sick and that's something we want to avoid,” said Chris Van Deusen, a spokesperson for the Texas Department of State Health Services.

While 98 percent of people in Texas are vaccinated according to state data, there is a growing number of parents opting out.

Texas went from just over 2,000 “conscientious exemptions” from immunizations in 2003 to more than 44,000 this year.

The highest exemption rate in the state is at Austin Waldorf School, a private academy in Southwest Austin.

Waldorf School Director Kathy McElveen said the school does not encourage parents one way or another to vaccinate. "We never question their decision, that's their decision, we just follow state law,” said McElveen.

More than 40 percent of their students have exemptions on file.

But as McElveen explained, that does not mean those exempted students have zero immunizations. Often, she explained, parents will get an exemption to vaccinate on a different schedule than the state mandates, or opt out of one of the vaccines, like chicken pox.

"If they opt out of just one, they still have to have an exemption on file so many of the students in our school that have exemptions on file are in fact vaccinated with all or some vaccines,” said McElveen.

KVUE did a further search of state data. According to the school's self-reported numbers, only 37.5 percent of Austin Waldorf's 2015 seventh grade student body had the range of immunizations.

That’s compared to 95 percent of Austin ISD's 2015 seventh grade class and 93 percent at Austin Discovery School, which has the second highest exemption rate in the city after Austin Waldorf at 30 percent.

McElveen says there's no cause for concern at Austin Waldorf. Many parents just chose to vaccinate on different schedules.

State data shows that over the past three years, both measles and chickenpox cases have gone down in Texas while cases of hepatitis A and mumps have gone up.

To see the raw data of school exemption percentages, click here.

For more on the school immunization coverage data, click here.