Body Politic: The Political Divide in Vaccine Uptake Across the United States

Abstract Background The COVID-19 pandemic exposed social disparities and science politicization, affecting vaccine acceptance in the United States (US). As Republican officials increasingly distance themselves from vaccination support amid rising misinformation, reassessing partisanship's role in vaccine hesitancy is crucial, particularly considering the 2024 US presidential election results and recent socio-demographic and health trends. Methods We conducted a cross-sectional ecological analysis of 3,224 US counties using publicly available data, including vaccination rates, election outcomes in 2020 and 2024, and demographic and health indicators. Spearman correlations and multivariate linear regression models assessed associations between Republican vote share and vaccine uptake, controlling for income, education, mortality, and healthcare access. Results Republican vote share was strongly and negatively associated with COVID-19 vaccination rates (r=-0.699, P<.001) and moderately negatively associated with flu vaccination rates (r=-0.422, P<.001). Each percentage-point increase in Republican vote share was associated with a 0.446% decrease in COVID-19 vaccine uptake in 2024 (P<.001), after adjusting for covariates. The partisan divide widened from 2020 to 2024. Conclusions Partisan divides in vaccination in the US have persisted and widened. Results signal a troubling trend in politicizing routine public health behavior, extending beyond pandemic-specific concerns. Key messages • Political partisanship strongly predicts vaccine uptake, with the gap between Republican and Democratic counties widening from 2020 to 2024. • Public health strategies must incorporate politically tailored interventions to increase vaccine acceptance in conservative communities.