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School Immunization Laws Are Making Kindergarteners Safer

School immunization laws are working

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The number of U.S. children fully vaccinated against potentially deadly diseases such as diphtheria and measles had been slipping before 2011. Since then, national declines have slowed or even reversed. Rates for kindergartners are noticeably higher than for children 19 to 35 months old because of state laws requiring them to have the full series of inoculations before they can enter the classroom. The laws vary, “but overall they say, 'We have to protect our children.' It's terrific,” says William Schaffner, professor of preventive medicine at Vanderbilt University. Vigilance remains needed, however; levels have eroded slightly for the older group. That may be because laws in some states do not require the entire series of recommended doses or allow parents to easily obtain exemptions. Young parents may seek to opt out because they do not think diseases are serious and may not have learned about them in middle or high school health classes, which tend to focus on subjects such as sexual activity and drug use.

How Many Doses?

The U.S. Centers for Disease Control and Prevention recommends four doses of DTaP vaccine and one dose of MMR vaccine by the time children are 19 to 35 months old. It recommends five doses of DTaP and two of MMR by ages four to six, which is what most states require for school entry. Data below are for these levels (graph on left).


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No More Exemptions

Some parents are determined to skirt kindergarten immunization laws, which can pull down a state's average. In 2016, when California ended exemptions based on a parent's religious or philosophical beliefs, medical exemptions—authorized by doctors or forged in their names—tripled, compared with 2015 (graph on right).

Credit: Jan Willem Tulp; Source: Centers for Disease Control and Prevention

Mark Fischetti was a senior editor at Scientific American for nearly 20 years and covered sustainability issues, including climate, environment, energy, and more. He assigned and edited feature articles and news by journalists and scientists and also wrote in those formats. He was founding managing editor of two spin-off magazines: Scientific American Mind and Scientific American Earth 3.0. His 2001 article “Drowning New Orleans” predicted the widespread disaster that a storm like Hurricane Katrina would impose on the city. Fischetti has written as a freelancer for the New York Times, Sports Illustrated, Smithsonian and many other outlets. He co-authored the book Weaving the Web with Tim Berners-Lee, inventor of the World Wide Web, which tells the real story of how the Web was created. He also co-authored The New Killer Diseases with microbiologist Elinor Levy. Fischetti has a physics degree and has twice served as Attaway Fellow in Civic Culture at Centenary College of Louisiana, which awarded him an honorary doctorate. In 2021 he received the American Geophysical Union’s Robert C. Cowen Award for Sustained Achievement in Science Journalism. He has appeared on NBC’s Meet the Press, CNN, the History Channel, NPR News and many radio stations.

More by Mark Fischetti

Jan Willem Tulp is an independent data experience designer from The Netherlands. He designs creative data visualizations for a wide variety of clients. You can find his work at http://tulpinteractive.com.

More by Jan Willem Tulp
Scientific American Magazine Vol 317 Issue 5This article was published with the title “Safer by Kindergarten” in Scientific American Magazine Vol. 317 No. 5 (), p. 84
doi:10.1038/scientificamerican1117-84

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