Quantifying the Rise in Anti-Vaccine Policymaking Across State Legislatures Through the State Vaccine Policy Project (SVPP).

Since the onset of the COVID-19 pandemic, lawmakers across the US have introduced legislation aimed at weakening existing vaccine-related policies (e.g., vaccine mandates in employment or educational settings). However, reports of anti-vaccine policymaking (AVP) across state legislatures have been largely anecdotal. We offer a first-of-its-kind effort to quantify and standardize reporting of the prevalence, characteristics, and correlates of AVP by introducing the State Vaccine Policy Project (SVPP) database; a content-coded record of every piece of vaccine-related legislation introduced across all US state houses from 2019 - 2023. SVPP data reveal that both the total volume and proportion of anti-vaccine bills introduced across state legislatures has been increasing steadily since the onset of the COVID-19 pandemic, with nearly 1 in 10 anti-vaccine bills signed into law during that period. We also show that the rise in anti-vaccine legislating is attributable primarily to the legislative actions of state lawmakers affiliated with the Republican party, and that dozens of anti-vaccine bills directly aim to reduce the scope of vaccine mandates. In addition to offering a standardized and exhaustive assessment of the growth of anti-vaccine policy making across US state legislatures, our work provides scholars with a unique dataset for studying changes in the vaccine policy environment.