Power and persuasion in the vaccine debates: an analysis of political efforts and outcomes in the United States, 1998-2012.

CONTEXT: This article examines trends in state-level childhood vaccine policies in the United States from 1998 to 2012 and explains the trajectories for both vaccine-critical and proimmunization legislative efforts. Successful mobilization by vaccine critics during the height of the autism and thimerosal scares (roughly 1998 to 2003) yielded a few state-level expansions for the most permissive type of exemption from vaccine mandates for public school attendance, those based on personal beliefs. Vaccine-critical positions, however, have largely become discredited. How has vaccine critics' ability to advance preferred policies and prevent the passage of unfavorable legislation changed over time? METHODS: We created a unique data set of childhood vaccine bills (n = 636), introduced from 1998 to 2012 across the 50 state legislatures, and coded them by type of effort (exemption, mandate, mercury ban, and information policies) and outcome. We then mapped out the trends in vaccine policies over time. In order to contextualize the trends we identified, we also reviewed numerous primary sources and conducted interviews with stakeholders. FINDINGS: In general, we found that vaccine critics' legislative success has begun to wane. In only 20 bills in our data set were vaccine critics able to change policy in their preferred direction via the legislative process. Only 5 of those wins were significant (such as obtaining a new philosophical exemption to vaccine mandates), and the last of these was in 2007. Critics were more successful at preventing passage of proimmunization legislation, such as mandates for the human papillomavirus (HPV) vaccine. CONCLUSIONS: Recent legislation in California, Oregon, and Washington that tightened philosophical exemptions by means of informational requirements suggests that vaccine politics may be entering another phase, one in which immunization supporters may be able to counter increasing opt-out rates, particularly in states with recent outbreaks and politicians favoring science-based policies.