A growing number of parents in McKinney ISD have filed for vaccine exemptions since 2003, when state lawmakers expanded the exemption process to include reasons of conscience, rather than only medical or religious reasons.
Districts are required by law to report the number of conscientious exemptions to the Texas Department of State Health Services each year. In the 2015-16 school year, the most recent in which data was collected, the rate of students in MISD who had filed for vaccine exemptions rose to 1.8 percent—more than double the state average.
The same pattern holds for other districts in Collin County, which has the 13th-highest exemption rate of the state’s 254 counties at 1.92 percent.
The trend, if it continues on its current trajectory, threatens to undermine what vaccine researchers call herd immunity, where a population’s high vaccination rates help slow the spread of vaccine-preventable diseases, protecting both the unvaccinated and people for whom vaccines are not fully effective.
“That is the biggest concern with those vaccination exemption rates rising is that we no longer have that herd immunity once you reach a certain percentage,” said Julie Blankenship, director of health services for MISD. “But we are only at 1.8 [percent], so we aren’t really at that point.”
Although the state health agency does not yet recognize a “significant concern statewide” as a result of the trend, aan agency spokesperson said the risk of outbreaks increases as
vaccination rates continue their steady decline in school districts throughout Texas.
“There’s not a number that I think we can point to that at ‘X,’ it’s going to be a problem,” said Chris Van Deusen, a spokesperson for the agency. “It’s really kind of a sliding scale, if you will. The more unvaccinated individuals you have, the more likely you could have some sort of outbreak.”
In neighboring Denton County, where more than 2 percent of students countywide have received conscientious exemptions, a top health official says herd immunity is already being undermined.
“Having twice the state average, that’s a concern to us because we believe vaccines are a good way to prevent communicable and infectious diseases,” said Matt Richardson, Denton County director of public health. “So we think [vaccination] is a good way to protect the public, and we think a 2 percent number is still too high.”
Policy and demographics
At least two proposals being considered by the Texas Legislature this session would make it more difficult for parents to obtain an exemption. House Bill 241 would require a doctor’s consultation before parents obtain an exemption; HB 126 would require parents to first review online education materials.
Another bill, HB 1124, would make it easier to obtain an exemption by making the relevant forms available for download on the state health agency’s website, simplifying the current multistep process that includes requesting a mailed form from the agency website and submitting a notarized affidavit to the child’s school.
Some have organized to lobby against legislative efforts to curb exemption rates, including Texans for Vaccine Choice, based in the North Texas suburb Keller.
“These bills would place a barrier between parents and their exemptions,” the group’s Director of State Policy Rebecca Hardy said. “These bills also assume the parents that are requesting these exemptions are uneducated, when in fact all the research shows that those that choose personalized vaccination schedules are, in fact, quite educated.”
A government study of data from the 2009 National Immunization Survey found that parents who delay or refuse vaccinations for their children are more likely than the average person to have graduated from college and have a household income at least four times the federal poverty line, among other factors associated with higher socioeconomic status.
The Centers for Disease Control and Prevention analyzed survey responses from a sample of 11,206 children and determined children were vaccinated at lower rates across the board if their parents believed vaccines could result in serious side effects or that too many vaccines could overwhelm a child’s immune system.
The study also found parents who delayed and refused vaccines are more likely to be white than those who neither delayed nor refused.
In Collin County, the median 2015 household income was $84,735, or more than four times the poverty level for a three-person household, according to U.S. Census surveys. Nearly half of Collin County adults age 25 and older had at least a bachelor’s degree, compared to 30 percent nationwide. Roughly six in 10 people in Collin County in 2015 were non-Hispanic whites, which was roughly equivalent to nationwide rates.
Because parents are not required to report their reasons for filing for conscientious exemptions, MISD health officials do not have a comprehensive picture of which parents are electing not to vaccinate their children or why.
Blankenship said some parents have filed for exemptions simply to delay an immunization, as opposed to others who may be acting based on information they read online.
The district has seen a number of exemption requests for 3-year-olds at the preschool level and seventh-graders, Blankenship said. Aside from anecdotal evidence, it is unclear why parents are opting out of the shots, she said.
Hardy, after citing a handful of examples of private and charter schools that have high exemption rates and no recent disease outbreaks, said her group promotes access to exemptions without weighing in on the scientific consensus on declining vaccination rates and herd immunity.
“They’re following their religious and other deeply held convictions,” Hardy said of parents filing for exemptions.
But state health officials say such examples of small populations that avoid outbreaks are not reflective of the broader risks associated with declining vaccination rates. For an outbreak to occur, Van Deusen said, it is not enough to simply have low vaccination rates; the disease, made rare by the widespread use of vaccines, must also be reintroduced to the population.
Diseases such as measles are sometimes introduced after a person close to the community travels to another country where the disease is still circulating, Van Deusen said. In 2013, a large church northwest of Fort Worth that promoted skepticism of vaccines saw nearly two dozen cases of measles after a member contracted it while visiting Indonesia, he said.
Monitoring vaccination rates
In Texas, residents can file for two types of vaccination exemption.
The first is a medical exemption, which requires a physician to confirm a vaccine would harm the health of a child.
The other method—which is tracked by the state—is an exemption based on reasons of conscience, including religious beliefs.
At MISD, officials have protocols for reacting to an outbreak but say they look to the state and county for guidance regarding vaccination rates.
The district has seen isolated cases of whooping cough, a disease for which students are regularly vaccinated, but nothing that qualified as an outbreak, Blankenship said. In the event of an outbreak, unvaccinated students—including those who are exempt for reasons of conscience—may be sent home from school for multiple days without an excused absence, Blankenship said.
The state agency that compiles the district exemption rates each year does not analyze it in great detail, leaving that up to independent researchers, Van Deusen said. And since there is no hard-and-fast cutoff for what exemption rates are considered too high, the state offers districts little guidance on that question.
Because exemptions are allowed by state law, the state has limited tools for addressing vaccination rate increases, Van Deusen said.
“Obviously, we fall back on the science and we talk about the benefits of immunization and how important they’ve been over the decades, since they were one of the ultimate achievements of public health in the 20th century,” Van Deusen said.
