Tennessee’s measles vaccination rate is much lower than it needs to be for community protection.
To reach so-called “herd immunity,” 95% of kindergartners should have their vaccine, according to the Centers for Disease Control and Prevention. Tennessee Department of Health numbers show only about 75% of kids ages 4 to 6 have their shots. In some areas, that rate is even lower. In Williamson County, which includes Franklin, the rate is less than half.
That’s especially relevant this year. There have already been more measles cases reported in the U.S. than in all of 2024. None have been in Tennessee, but there have been several in Kentucky and Georgia.
Kids are either never getting their measles shots, or they’re getting them late, said Dr. John Heise, a Chattanooga physician who represents Tennessee’s chapter of the American Academy of Pediatrics.
He said those who opt out tend to cite concerns about autism. That claim originated from a now-retracted article about the measles, mumps and rubella combination vaccine in The Lancet medical journal. It published in 1998. Since then the study has been disproven several times, it has been revealed that personal injury lawyers who were suing vaccine makers funded the study and senior author Andrew Wakefield lost his medical license.
“We still kind of get questions from that, even though that’s been proven totally false over and over,” Heise said.
But he said it was more common for children to be simply behind on the shots. Parents ask to slow the schedule of vaccines and spread them over a longer period of time.
“They’re worried about the side effects and overwhelming the immune system — not realizing we’ve been doing this for decades,” Heise said. “And we do tell them that if we do it the way they’re asking, they’re actually going to be getting more shots than they would if we were able to do the combinations.”
One reason for that: younger kids can get a shot that combines the measles, mumps and rubella vaccine with the one that protects against varicella. But if they wait until they are older, they have to get a separate varicella shot.
Unlike COVID-19 and the flu, vaccines against the measles, mumps and rubella last more than a year, said Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center.
“If you’ve had a standard two-dose vaccination series with measles vaccine, you have a 98% chance of being fully protected throughout your life,” he said. “That’s about as good as it gets.”
Some people didn’t get the standard two doses. Those born between 1957 and 1958 likely got a vaccine with a different recipe — one that’s not quite as good. And those born from 1968 to 1989 might have gotten just one dose. That offers pretty good protection.
“But if you’d like to get up to 98%, you can get that second dose,” Shaffner said.
