Mississippi has the country’s highest rate of vaccinated kindergartners. (Joe Raedle/Getty Images)

Reid Wilson is the author of Read In, The Post’s morning tipsheet on politics. Read more from Outlook and follow our updates on Facebook and Twitter.

The measles outbreak that has spread from California to Arizona and beyond has renewed debate over whether parents should be required to vaccinate their children. Medical professionals almost unanimously agree that doing so prevents the spread of dangerous diseases with little or no risk, while some parents on the left and the right are concerned about autism and big-government interference.

In Mississippi, the debate has long been settled. Since the 1970s, the state has required parents to vaccinate any child attending public or private schools, and it’s very difficult for anyone to claim an exemption . The state Supreme Court ruled in 1979 that religious exemptions violated the state constitution, and Mississippi is one of 32 states that don’t allow exemptions for philosophical reasons.

The result: A stunning 99.7 percent of the 45,719 Mississippi kindergartners had received the measles, mumps and rubella vaccine, as well as the diphtheria, tetanus toxoids and pertussis vaccine, according to an October report from the Centers for Disease Control and Prevention.

Mississippi hasn’t had a case of measles since 1992, according to Thomas E. Dobbs III, the state epidemiologist. In the United States, there were about 60 cases of measles, on average, each year between 2001 and 2011, though there were 644 cases reported in 2014, according to the CDC.

“The vast majority of Mississippians support the need for immunizations, so we do have a good historical relationship with our providers and the vast majority of our parents,” Dobbs said in an interview.

North Carolina, Utah and Hawaii were the only other states where more than 98 percent of children had gotten the MMR vaccine. At the bottom of the pile, fewer than nine in 10 children had received the MMR vaccine in Arkansas, Idaho, Kansas, Maine, Pennsylvania, Washington and the District of Columbia. In Colorado, just 81.7 percent of kindergartners had received MMR shots, the lowest rate in the country.

Skepticism has found its way into Mississippi, however. Dobbs said that the number of medical exemptions — 135 in 2014 — has more than doubled in recent years. This week, legislators fended off another attempt to allow religious and philosophical exemptions.

Holding a firm line on those exemptions has kept nasty outbreaks out of Mississippi schools. Efforts to roll back similar exemptions elsewhere could be a real shot in the arm to other states.

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