Oregon had the highest number of kindergarteners in the country opting out of immunizations in 2012, and the rate inched up from 5.8% to 6.4% this year.
A few Oregon counties reached exemption rates as high as 15.2 percent in Wallowa County, 13.5 percent in Josephine County and 13.2 percent in Grant County.
Public health officials hope for at least a 95 percent vaccination rate. When rates dip lower, the risk of measles, meningococcal disease and polio increases.
Read more at The Statesman Journal.