See states’ kindergarten vaccination rates—from highest to lowest
Even as cases of diseases such as measles rise, childhood vaccinations are declining, thanks to changes in public health policies and antivaccine sentiment, experts say
By Jackie Flynn Mogensen & Sanidhya Sharma edited by Claire Cameron
It’s back-to-school season. For most parents of the U.S.’s school-aged kids, that means filling out medical forms and making sure the children are up to date with their vaccinations. But this ritual is shifting: The 2025–2026 school year saw a record low number of kindergartners vaccinated for measles, polio, tetanus, and more. At the same time, more kids in this age group had exemptions from at least one vaccine that school year than at any other point in the past decade.
Meanwhile the diseases these vaccines protect against are making a comeback. Take measles, for example: The U.S. officially eliminated the disease in 2000 with the combined measles, mumps and rubella (MMR) vaccine. But in the past few years, that progress stalled, and measles is on the rise. So far this year, officials have recorded more than 2,500 measles cases in the U.S.—the most since the virus was wiped out in the U.S. 25 years ago.
We analyzed the latest vaccine data to better understand what states in the country are most at risk of an outbreak and how vaccination rates are changing among the U.S.’s schoolkids.
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More than 90 percent of U.S. kindergarteners still get the MMR vaccine. But according to the latest data from the U.S. Centers for Disease Control and Prevention, MMR vaccination rates among kindergarteners have fallen from about 95 percent to 92.4 percent in the past 10 years. The country saw similar declines for vaccines that protect against polio, hepatitis B, and diphtheria, tetanus and acellular pertussis.
Sanidhya Sharma; Source: "Vaccination Coverage and Exemptions among Kindergartners," U.S. Centers for Disease Control and Prevention. Updated August 17, 2026 (data)
For the most contagious diseases, even a small dip in vaccination can trigger population-wide problems. “Measles is the single most contagious disease that we know of,” says Adam Ratner, a professor of pediatrics and microbiology at New York University. “It is more contagious than flu or COVID or polio or Ebola or anything else you can think of.” Around 90 percent of unvaccinated people exposed to the virus will become infected.
In most states, specific childhood vaccinations, including MMR, are required to attend public school. Depending on state policy, parents may be able to opt out of certain or all vaccines by claiming an exemption for medical, religious or philosophical reasons. Nationwide, the proportion of kindergartners with nonmedical exemptions has doubled in recent years—from about 1.9 percent 10 years ago to 4 percent today.
Sanidhya Sharma; Source: "Vaccination Coverage and Exemptions among Kindergartners." U.S. Centers for Disease Control and Prevention, August 17, 2026 (data)
Not all states are equal. Many have seen sharp declines in vaccination rates—kindergarten MMR vaccinations in Idaho, for instance, has seen a drop of 15 percentage points in the past decade. Others have remained mostly stable or even increased, however. In the past 10 years in Connecticut, for instance, kindergarten MMR rates have increased from 96.7 percent to 98.6 percent in the 2025–2026 school year. In Maine, rates have risen from 94.9 percent to 98 percent over the same period. And in New York State, rates have stayed relatively flat over the past decade, with a slight rate uptick from 97.3 percent to 97.7 percent.
Sanidhya Sharma; Source: "Vaccination Coverage and Exemptions among Kindergartners." U.S. Centers for Disease Control and Prevention, August 17, 2026 (data)
In general, states that don't allow personal exemptions have higher vaccination rates, says Lori Handy, an associate director at the Vaccine Education Center at the Children’s Hospital of Philadelphia. (About two thirds of states don’t allow personal exemptions, although only four states prohibit both personal and religious exemptions.)
Source: Read the original article on www.scientificamerican.com
