Washington state is home to Bill and Melinda Gates, champions of childhood vaccines across the globe. Its university boasts cutting-edge vaccine research. But when it comes to getting children immunized, until recently, the state was dead last.
“You think we’re a cut above the rest,” said Maxine Hayes, state health officer for Washington’s Health Department, “but there’s something in this culture out West. It’s a sort of defiance. A distrust of the government.”
The share of kindergartners whose parents opted out of state immunization requirements more than doubled in the decade that ended in 2008, raising alarm among public health experts. But last year, the legislature adopted a law that makes it harder for parents to avoid getting their children vaccinated, by requiring them to get a doctor’s signature if they wish to do so. Since then, the opt-out rate has fallen fast, by a quarter, setting an example for other states with easy policies.
For despite efforts to educate the public on the risks of forgoing immunization, parents are increasingly choosing not to have their children vaccinated, especially in states that make it easy to opt out, according to a study published today in The New England Journal of Medicine.
And while the rate of children whose parents claimed exemptions remains low — slightly over 2 percent of all kindergarten students in 2011, up from just over 1 percent in 2006 — the national increase is “concerning,” said Saad Omer, an assistant professor of global health at Emory University who led the study.
Families of unvaccinated children tend to live in close proximity, increasing the risk of a hole in the immunity for an entire area. That can speed the spread of diseases such as measles, which have come back in recent years.
The opt-out rate increased fastest in states like Oregon and Arizona — and Washington, before its law changed — where it was easy to get an exemption. In such states, the rate rose by an average of 13 percent a year from 2006 to 2011, according to the study. In states that made it harder to get an exemption from vaccination, such as Iowa and Alabama, the opt-out rate also rose, but more slowly, by an average of 8 percent a year. Mississippi and West Virginia allow no exemptions.
Vaccines are among the most important achievements of modern medicine. Since the first major types came into broad use in the 1940s, they have drastically reduced deaths from infectious diseases like polio and measles. But the virtual disappearance of these diseases has lulled parents into considering the vaccines against them as less necessary, public health experts say.
“Vaccines are the victims of their own success,” said Paul Offit, chief of infectious diseases at the Children’s Hospital of Philadelphia. “When they work, nothing happens.”
A distrust of the medical establishment has also fueled skepticism about vaccines. And while the Internet is a powerful source of information, it has also allowed the rapid spread of false information, such as the theory by Andrew Wakefield, a former British surgeon, that the measles-mumps-rubella vaccine was linked to the onset of autism.
“With the Internet, you can have one cranky corner of Kentucky ending up influencing Indonesia,” said Heidi Larson, a lecturer at the Project to Support Public Confidence in Immunization, at the London School of Hygiene and Tropical Medicine.
Parents who refuse vaccines tend to be more educated, and often more affluent than the average, researchers say.