Before 2003, only a few hundred Arkansas schoolchildren did not receive standard childhood vaccinations due to health conditions or religious beliefs.
But once legislators changed the law and allowed parents to cite a "philosophical" objection, the rate of students forgoing shots has been rising, and health officials say the result is that people are unnecessarily contracting — and sometimes dying — from diseases ranging from whooping cough to the flu.
Dr. Dirk Haselow, chief of immunizations at the Arkansas Health Department, said the number of medical and religious exemptions has fallen slightly since 2003, but there was a marked increase in the philosophical exemption.
At present, there is a large outbreak of whooping cough in the Pacific Northwest. Whooping cough is particularly dangerous for infants, whose airways can be closed by swelling associated with the infection. During an outbreak in California last year, 10 infants died.
And there are occasional cases of measles, a disease that had been almost wiped out in the U.S. Haselow said measles' recurrence parallels the rise in people going unvaccinated, and the main reason is "bad information" that links immunizations with autism.
"There was ... some bad research that was in the press years ago that has been retracted. Many parents have held onto the misconception that (the measles, mumps and rubella vaccine) causes autism. This is a very hard opinion to change," he said.