AUSTIN (KXAN) — More than half of Texas’ counties have MMR vaccination rates among kindergartners below the threshold for what the Centers for Disease Control and Prevention says is needed for herd immunity.
The CDC says most people are protected from measles, mumps and rubella through herd immunity, also known as community immunity, when more than 95% of people in that community are vaccinated.
As of the 2024-25 school year, kindergarten students in 139 counties did not meet that threshold — 55% of the state’s counties — according to Texas Department of State Health Services data collected and analyzed by NBC News in partnership with researchers at Stanford University.
Just a decade ago, only 42 counties were below the threshold.
The CDC typically recommends two doses of the MMR vaccine — the first administered between 12 and 15 months, and the second between the ages of 4 and 6. In Texas, being vaccinated is required for all students at public and private schools, but parents can request an exemption, either for medical reasons or for “reasons of conscience,” such as religious objections.
The map below shows the MMR vaccine coverage rate in each county across the state. Counties with a lower coverage rate — meaning a higher share of students have an exemption — appear darker on the map.
Irion County, west of San Angelo, has the lowest vaccine coverage rate. Only about two-thirds of kindergartners in the 2024-25 school year were fully vaccinated. The other third of students had non-medical exemptions.
Gaines County, southwest of Lubbock, had the second-highest share of kindergartners with non-medical exemptions, at 19.49%. The county was the epicenter of a deadly measles outbreak earlier this year. A total of 762 cases were reported tied to the outbreak, 414 of which were in Gaines County alone. Over the course of the outbreak, 99 people were hospitalized, and two children died.
In addition to medical and non-medical exemptions, the state’s ‘Annual Report of Immunization Status’ also lists provisional enrollment and delinquency as a reason why a child may be inadequately vaccinated. For this reason, the percentages in the map above may not add up to 100%.
Vaccine rates have dropped in recent years
In the 2024-25 school year, 20 counties had vaccine coverage rates among kindergartners of 100%, down from 43 counties a decade ago.
Coverage rates have dropped in all five of the state’s largest counties over the past 10 years. In Harris County, home to Houston, the rate dropped from 96.6% to 91%. Dallas County’s rate dropped from 98.3% to 90.2%. In Travis County, the rate fell from 95.2% a decade ago to 86.7%.
In the KXAN viewing area, the decrease is particularly noticeable in Blanco County. In the 2014-15 school year, 94.9% of kindergartners were immunized — right around the threshold needed for herd immunity.
By the 2021-22 school year, the rate had fallen to 89.7%, before reaching a low of 85.6% the following year. The rate in Blanco County in the 2024-25 school year, the most recently-available data, sat at 86.1%.
Not every county has seen a decrease though. Caldwell County’s coverage rate has remained fairly consistent over the past decade. Other than a dip in the 2016-17 school year, the county has stayed above the herd immunity threshold, with a coverage rate of 97.3% in the 2024-25 school year.
A Worrying Trend
Across the U.S., experts say vaccination rates tend to be higher in urban areas than in rural ones. This pattern is less true in Central Texas, where several more rural counties surrounding Austin – including Bastrop, Caldwell and Hays counties – report MMR vaccination rates of 95% or higher.
Dr. Peter Hotez, dean of the National School of Tropical Medicine, said anti-vaccination sentiments have increased in Austin in recent years.
“Historically, meaning over the last 10–15 years, we have seen anti-vaccine activist groups be more active in the Austin area, and that may account for that aberration,” Hotez told KXAN.
Hotez said anti-vaccine activism intensified during the COVID-19 pandemic. He’s concerned that lower vaccination rates will leave Texas vulnerable to future outbreaks.
“We’ve had one of our worst years for measles in Texas this year. Other diseases will follow, like whooping cough, pertussis. Hopefully, we won’t see it spill over to polio,” Hotez continued.
In Texas, both the polio vaccine and the Tdap vaccine — which protects against tetanus, diphtheria and pertussis — are required, according to DSHS.
After the 2025 Texas measles outbreak, Hotez noted an increase in families choosing to vaccinate their children with the MMR vaccine.
He said health education is key to preventing future epidemics.
“With efforts that are going on in Florida, announced by the Florida Surgeon General, [to end vaccination mandates] – I would hate to see something like that happen in Texas,” Hotez said. “We know what would happen. It would cause a return of measles and pertussis, and hospitalizations and deaths would follow.”
