Abstract
This study reviews trends in available public opinion data on vaccines, which mainly cover 2001-2021. Four general findings emerge. First, Americans have been progressively hearing more information about vaccines over the past two decades. Second, attitudes regarding vaccines’ utility, safety, and appropriateness of requirements have mostly declined during this same period. Third, trends in reported vaccination behavior differ from trends in attitudes, and also vary across different vaccine types. The pattern of these differences suggests a strong influence of public policies on vaccine behavior. Finally, an analysis of trends among Democrats and Republicans suggests that vaccine attitudes and behavior were mostly apolitical up until around 2008 or so. But since then—and clearly prior to the politicization of the COVID-19 pandemic—the parties have increasingly diverged on vaccines. While Republicans have continued to become more vaccine skeptical, Democrats have actually reversed the overall trend and become more vaccine supportive.