For the 2011-2012 school year, an estimated 2.2% of all U.S. children enrolled in kindergarten received exemptions to vaccination, according to a report from the Centers for Disease Control and Prevention.
There were 89,133 exemptions reported in the estimated kindergarten population of 4,124,185 children, but states may have reported exemptions for one or more required vaccines, so "it is unlikely that children with an exemption were completely unvaccinated," the CDC noted (MMWR 2012;61:647-52).
Among the individual states, Alaska had the highest exemption rate (7.0%) and Mississippi the lowest (less than 0.1%). Compared with the 2009-2010 school year, the largest increase in exemption rate came in Arkansas, which went from 0.6% to 3.9%. The largest decrease occurred in Nebraska, which dropped from 3.8% to 1.5%, the report said.
The exemptions come in two basic types, medical and nonmedical, with the nonmedical category divided into religious and philosophic exemptions.
Texas had the largest number of medical exemptions (2,058), Illinois had the highest number of religious exemptions (7,270), and California had greatest number of philosophic exemptions (12,665). Illinois’ number of religious exemptions was 2.6-fold greater than that of the next-highest state, Florida, which had 2,771, and California’s number of philosophic exemptions was 2.4 times higher than that of Michigan, which came in second at 5,213, according to the CDC.
