See Vaccine Exemptions in Texas by School District

_{*Editor's note: This story has been updated throughout.}

The heavily Democratic and rapidly growing Travis County doesn't have much in common with its neighbor about 80 miles to the northwest, the conservative and largely rural Lampasas County.

But other than both being predominantly white, the counties have another glaring similarity: They have some of the state’s highest percentages of schoolchildren with exemptions from state vaccination laws. At 5 percent, Lampasas County has the state's highest rate, with 182 exempted students. And at 1.75 percent, Travis County has the highest among the state's five most populous counties, with just over 2,900 exempted students. 

More than 38,000 students — about 0.75 percent of the state's overall school-age population — had nonmedical exemptions to school immunization laws statewide in the 2013-14 school year, according to Texas Department of State Health Services data. That figure, which includes students at both public and accredited private schools, has soared from just under 3,000 — or 0.09 percent — in 2004. 

The overall nonmedical exemption rate in Texas is below the national average of 1.8 percent. But it is much higher in certain pockets of the state. 

Medical experts believe that the climbing number of children whose parents opt them out of vaccines — as well as the tendency of those who do not immunize to gather in the same communities — has led to an increased frequency of infectious diseases like measles. 

Schools report the number of students with exemptions to the Department of State Health Services annually. Though the highest rate reported was at a public school — Calvert ISD, about 50 miles east of Temple, where the parents of almost three-quarters of its 143 students obtained exemptions — private schools tended to have higher exemption rates than public schools. 

The rates at one Travis County private school, Austin Waldorf, where 48 percent of students have a vaccine exemption, more than doubled the next highest rate, which was 17 percent at Sterling Classical School in Williamson County.

By comparison, only seven public school districts had exemption rates higher than 5 percent. After Calvert ISD, which did not return a request for comment, the second-highest rate was at the Austin Discovery School, a charter school. The third highest was in Denton, where 12 percent of the North Texas district's 25,000 students had exemptions.

When reached by The Texas Tribune on Wednesday, Denton ISD spokesman Mario Zavala disputed the accuracy of the data, saying the district’s numbers were based on the number of vaccines with exemptions instead of the number of students. Christine Mann, a spokeswoman for the state health department, said that was not possible because students only file one form when they receive exemptions. (See an attached copy of the form.)

Zavala said Thursday that the district had confirmed it had submitted incorrect numbers to the state. He said the district was in the process of fixing the error, which he said it had made for several years when reporting exemptions, with the state health department. According to district numbers for the 2014-15 school year provided to the Tribune, 513 of Denton’s now 27,134 students have exemptions to at least one state-required vaccine, putting its rate at 1.9 percent.

Federal health officials reported 644 cases of the measles last year, the highest number since the disease was considered eradicated in the U.S. in 2000. Since Jan. 1, 102 people across 14 states, including one in Texas, have contracted measles, many of them linked to exposure at Disneyland, the California amusement park. Almost all who have contracted it were not vaccinated against the disease, which can be fatal, as well as cause other afflictions like pneumonia and encephalitis.

Texas had a measles outbreak in 2013, when more than 20 people contracted the disease in the Dallas-Fort Worth area. The cases were traced to the Eagle Mountain International Church, which is led by pastors who express skepticism about vaccines. A man who had been infected with the disease in Indonesia had recently visited the mega-church.

State law requires that children at all public and private schools have 10 different immunizations, including for tetanus, measles and pertussis, the bacterial disease known as whooping cough. Generally, those vaccines must happen by the time students are in kindergarten, though others, like for hepatitis B, occur in later grades.

All but two states — Mississippi and West Virginia — grant exemptions from school immunization requirements on religious grounds. Texas is among 20 states that also waive requirements because of personal beliefs, according to the National Conference of State Legislatures. 

In Texas, parents opt out of school immunization requirements through what's known as a "conscientious exemption" form filed with their child's school at the start of the year. In an affidavit listing each of the vaccines the student will not receive, parents are asked to confirm they understand the risks of not vaccinating and that their child could be excluded from school in the event of an epidemic or public health emergency.

Students who received waivers because of a health complication, like having a weakened immune system from cancer treatment or allergic reactions, are counted separately.