The influence of local political trends on childhood vaccine completion in North Carolina.

Abstract

In North Carolina (NC), a political swing state that permits both medical and religious exemptions to school vaccination, rapid changes in the electorate have coincided with a vigorous political debate over vaccine laws and an increase in the number of exemptions claimed from vaccine requirements. We aimed to determine whether county-level changes in political affiliation, determined from publicly available voting records, were associated with changes in the rate of vaccine exemptions reported at kindergarten entry in NC. We analyzed data from the 2009-2010 to the 2016-2017 school years for each of 100 NC counties. We used NC State Board of Elections and Ethics Enforcement data to track voter registration trends at the county level, comparing the percent of voters registered as Republican, Democrat, or other (mostly unaffiliated). Vaccination exemption rates were obtained via the NC DHHS and represented a percentage of the cohort entering kindergarten in that year. Statewide, the rate of religious vaccine exemptions increased from 0.68% in 2009-2010 to 1.10% in 2016-2017. On multivariable analysis including 800 county-years, a 1% increase in voters with neither Republican nor Democratic affiliation was associated with 0.04% increase in the county's vaccine exemption rate. In NC, the increase in vaccine exemption rates was primarily associated with an increasing share of voters affiliating with neither major party. This finding suggests mistrust in social institutions, including both government and medicine, extends beyond the platforms of traditional political parties.