Increasing numbers of Arizona parents choosing vaccine exemptions for kids

A recent study found vaccination rates lower among Arizona kindergartners attending charter schools that those who attend public schools.

Researchers at the University of Arizona found more than 2,000 Arizona kindergartners were not vaccinated for the 2010-2011 school year because state law allows for exemptions based on personal beliefs, according to SFGate.com.

The study, published online in the journal Vaccine, shows that approximately 6.2 percent of kindergartners in charter schools were exempted, while only 2.3 percent of public school kindergartners opted out. The researchers did not calculate the number of exemptions at individual or private schools.

More than one in five Arizona schools had exemption rates that were above five percent in 2010-2011. Eight percent of schools in the state had rates that exceeded ten percent of more.

"These areas become higher risk for diseases we are trying to vaccinate against," Dr. A.D. Jacobson, a past chief of ambulatory pediatrics at Phoenix Children's Hospital, said, SFGate.com reports. "If you can get a 95 percent immunization rate, you will have a herd immunity, and it will be unusual to see outbreaks."

Public health officials have recommended that no more than five to 10 percent of the population remain unvaccinated. When the number of unvaccinated children in a school passes the 10 percent mark, the risk of an outbreak increases dramatically.

Over the past decade, the number of personal exemptions in Arizona has doubled. At the same time, outbreaks of measles, mumps and pertussis in the state rose.