An increasing number of parents in more than half the states in the United States are choosing not to give their children vaccinations required by schools, The Associated Press found in an analysis of state health department student vaccination data. In eight states, more than 1 in 20 public school kindergartners do not get all the shots schools require, according to the AP.

Depending on where they live, parents can opt out of vaccinations for medical, religious or philosophical reasons, the AP reported.

Alaska had the highest vaccination exemption rate in 2010-11, the AP analysis found: almost 9 percent. In Colorado, 7 percent of kindergarteners had skipped shots, in Minnesota, 6.5 percent, and in Vermont and Washington, 6 percent, with similar exemption rates in Oregon, Michigan and Illinois.

According to the AP:

Exemption seekers are often middle-class, college-educated white people, but there are often a mix of views and philosophies. Exemption hot spots like Sedona, Ariz., and rural northeast Washington have concentrations of both alternative medicine-preferring as well as government-fearing libertarians.

In a separate study, 61 percent of pediatricians surveyed in Washington state said they were willing to deviate from the immunization schedule developed by the Centers for Disease Control and Prevention, the American Academy of Pediatrics and the American Academy of Family Physicians, NPR reported. A child gets 25 shots in the first 18 months of life on that vaccination plan.

The study, published in the journal Pediatrics, indicated that the doctors were willing to delay some vaccinations, like those against hepatitis B, chicken pox and polio, to maintain a relationship with skittish parents, NPR reported.

With their own children, 96 percent of pediatricians surveyed in the Pediatrics study said they would stick to the recommended vaccination schedule, NPR reported.

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