The article suggests an intriguing reason for these refusals:
It is the absence, or close to it, of some illnesses in the United States that keep some parents from opting for the shots. Worldwide, 242,000 children a year die from measles, but it used to be near one million. The deaths have dropped because of vaccination, a 68 percent decrease from 2000 to 2006.
“The very success of immunizations has turned out to be an Achilles’ heel,” said Dr. Mark Sawyer, a pediatrician and infectious disease specialist at Rady Children’s Hospital in San Diego. “Most of these parents have never seen measles, and don’t realize it could be a bad disease so they turn their concerns to unfounded risks. They do not perceive risk of the disease but perceive risk of the vaccine.”
Most of these concerns, however, are unfounded: the safety risk of most vaccines are negligible. And failing to vaccinate not only puts the non-vaccinated child at risk, but also his or her playmates. Even effective vaccines do not work 100% of the time, so a vaccinated child is not necessarily protected from his or her non-vaccinated friends.
For more information, see the Centers for Disease Control (CDC) fact sheet on common vaccinations.