Be it wealth, health, or education, when it comes to most measures of well-being, there is one state that reliably comes in last place. Mississippi is so used to trailing the pack in these rankings that it was a surprise when the state moved up to #49 in the annual Kids Count report last year. It was the first time in 24 years, since the Annie E. Casey Foundation first issued its survey, that Mississippi didn’t sit at the very bottom. (It fell back to last place in 2014.)

But there’s one indicator where Mississippi’s children outperform every other state: childhood vaccination rates. Yet, as the state that always seems to be struggling finds true success in this health measure, some residents are complaining its only evidence of a health department gone too far.

All states have some kind of requirement that mandates the vaccines children five and older must receive before they can enter public schools or state-licensed daycares. For the 2013-2014 school year, practically 100 percent of Mississippi’s 45,000 kindergartners were up-to-date on their required immunizations, according to newly released statistics from the Centers for Disease Control and Prevention (CDC).

The median coverage for the two-dose measles, mumps, and rubella vaccine (MMR) was 94.7 percent; 95.0 percent for diphtheria, tetanus, and pertussis (DTaP); and 93.3 percent for two doses of varicella vaccine in states that require it. Colorado had the lowest rates with 81.7 percent for MMR; 80.9 percent for DTaP; and 81.7 percent for varicella.

Of the 49 states, 27 did not meet the CDC’s 95 percent target rate for one or more of the vaccines. A small, but growing number of parents in these states are using exemptions that allow children to enroll in public schools while opting-out of the vaccine requirement for medical, religious, or philosophical reasons. The median total exemption rate was 1.8 percent this year, the same as in 2012-2013. Oregon led the country with over seven percent of its Kindergarteners citing a non-medical reason for their noncompliance.

In Mississippi, there were just 17 medical exemptions in the state, less than 0.1 percent of the total student population. And Mississippi is one of only two states—the other is West Virginia—that allows neither religious nor philosophical exemptions.

Children not yet under the school requirements ages 19 to 35 months also have higher vaccination rates than the rest of the country. Around 77 percent of Mississippi’s babies are fully immunized compared 68 percent in the country overall.

“Mississippi’s high immunization rates for children enrolled in kindergarten indicate a success for providing the best protection available to our children,” Joy Sennett, Director of Communicable Diseases at the Mississippi State Department of Health, said in an email to The Daily Beast. “Mississippi’s strong school entry law protects immunized children as well as others around them who can’t be immunized because of age or valid medical reasons. School vaccination requirements are one of the best methods of assuring that our children can be protected.”

Despite the rare tick in Mississippi’s win column, not every resident is happy with the state’s rigidity. In a letter to the editor published in a local paper, Lindey Magee, co-director of the group, Mississippi Parents for Vaccine Rights (MPVR), called her state’s laws “archaic” and “barabaric.”

“Mississippi families are being exploited for its reputation of ignorance and lack of education,” the Macomb mother of two wrote.

A “couple of thousand families” make up MPVR’s coalition, according to Magee (1,858 people “like” the group’s Facebook page) and they’ve banded together in efforts to change the existing law to allow for philosophical vaccine waivers.

Like others in the anti-vaccine movement, MPVR eschews that description. They aren’t anti-vaccine, but pro-choice, they say. They also claim that mothers in Mississippi are being bullied by the Department of Health and their doctors are being forced to practice bad medicine.

Their concerns about vaccines are many. They cite examples of vaccines supposedly causing maladies from ADHD to eczema, and say the mandated schedule calls for too many shots, too soon, and in too short a time span. MPVR’s blog is filled with stories of parents who say their children reacted to the shots by regressing developmentally, or pulling away and showing signs of autism.

Health officials , doctors and researchers roundly agree that these concerns are unfounded.

Despite several years of lobbying, so far, the MPVR has been unsuccessful in its attempt to pass a measure.

The data suggests that’s a good thing.

This year was a record one for measles in the U.S., with 18 outbreaks, and almost 600 cases reported in 22 states in 2014.

In California, where a recent resurgence of measles and whooping cough has sickened the unvaccinated, parents are still opting out of their mandated vaccines at twice the rate of 2007. In 2013-2014, 3.3 percent of kindergarteners were enrolled with exemptions.

Washington State was also hit especially hard by the reappearance of the disease that had already been eliminated in 2000, with the highest number of measles cases since 1996. Washington also had one of the largest exemption rates last year, at 4.7 percent, according to the CDC report.

Meanwhile, the last outbreak of measles in Mississippi was reported in 1992, according to the state department of health.

“Immunizations are one of the most important things we can do for our kids, Dr. Mary Currier, the state health officer said in a video promoting the state’s success. “We’ve pretty much done away with [vaccine-preventable diseases] in our state because we have such good immunization rates.”