The percentage of school children obtaining exemptions from required vaccinations for nonmedical reasons is increasing, a new report says.
In 2011, just over 2 percent of school children were exempt from getting their vaccines for nonmedical reasons, up from about 1 percent in 2006, the report found.
"Our results show that nonmedical exemptions have continued to increase, and the rate of increase has accelerated," in recent years, the researchers at Emory University wrote in a letter published today (Sept. 20) in the New England Journal of Medicine.
All U.S. states allow children to be exempt from vaccination requirements for medical reasons — some children are allergic to vaccines, others have conditions that severely compromise their immune systems, and could make vaccination dangerous to a child's health.
In addition, 48 states allow exemptions for nonmedical reasons (Mississippi and West Virginia do not). Nonmedical exemptions can be granted for religious reasons or philosophical reasons, though fewer states allow philosophical exemptions than religious ones.
For their report, researchers used data on vaccine exemptions from the Centers for Disease Control and Prevention for school years 2005–2006 through 2010–2011.
They found that the rates of nonmedical exemptions were 2.5 times higher in states that allowed philosophical exemptions, compared with states that allowed only religious exemptions.
However, the rate of exemptions was rising faster in states that allowed only religious exemptions, the report said.
The researchers also looked at state exemption rates in terms of how difficult exemptions are for parents to get — some states use a standardized form to request exemptions and make this form available at schools, others require parents to go though the state health department, or require a specifically worded letter or notarization.
Over the study period, the exemption rates were higher in states with "easy" exemption policies, compared with states with "difficult" policies. In 2011, the average exemption rate in states with easy policies was 3.3. percent, while it was 1.3 percent in states with difficult policies.
"In an earlier analysis of data from 1991 through 2004, we found an increase in exemption rates only in states with philosophical exemptions and in states with easy exemption procedures," the researchers said.