Up to 57,000 children whose parents who opted out of school vaccinations could fuel an outbreak of measles in Texas, according to a Baylor College of Medicine dean. The numbers of non-vaccinated children is 20 percent higher than a report from 2003.

“New numbers from the Texas State Health Department indicate that we have up to 57,000 kids whose parents have opted out of vaccines for school,” Dr. Peter Hotez said during an interview with KHOU CBS11. Hotez serves as the dean of the National School of Tropical Medicine at Baylor College of Medicine. He also serves as the director for vaccine development at Texas Children’s Hospital in Houston.

“I’m very worried about measles coming back to Texas just like they did in Minnesota last year,” the doctor explained. Minnesota officials witnessed a measles outbreak last year that left 79 people ill. Most of those were children under the age of ten.

The doctor says parents should make certain their children are vaccinated because they immunizations are “safe and lifesaving.”

“The anti-vaccine groups are very powerful, very well organized and they make effective use of social media, but what they’re putting out is misinformation,” Dr. Hotez explained. He urged parents to take the opportunity to get their children vaccinated before the start of school this month.

Reports indicating that 57,000 children are not properly vaccinated comes from a recent report from the Texas Department of Health, KHOU reported.

The parents of nearly 600 kindergartners in the Houston area opted out during the 2016-2017 school year, the Public Library of Science’s medical journal recently reported. This puts Harris County as number seven on the list of the nation’s 15 worst counties, KHOU reported. Dr. Hotez says this trend needs “to stop and fast.”