The Relationship Between Political Affiliation, Perceptions of Science and Scientists, and Perceived Safety and Effectiveness of the MMR, Flu, and COVID-19 Vaccines: United States, 2024.

Abstract

<b>Objectives.</b> To examine the associations between political party identification, perceptions of science and scientists, and perceived safety and effectiveness of the measles, mumps, and rubella, flu, and COVID-19 vaccines. <b>Methods.</b> We used multiple regression analyses to examine survey data collected in November 2024 from a national probability sample of 1763 US adults. We measured perceptions of science and scientists using the Factors Assessing Science's Self-Presentation (FASS) scale, which assesses beliefs that scientists are credible, prudent, and unbiased and that science is beneficial and self-correcting. <b>Results.</b> Respondents perceived the measles, mumps, and rubella vaccine as the safest and most effective (mean safety score = 3.54 [SD = 0.71]; mean effectiveness score = 3.63 [SD = 0.68]) and the COVID-19 vaccine as the least safe and effective (mean safety score = 2.98 [SD = 1.07]; mean effectiveness score = 2.81 [SD = 1.02]). After adjustment for FASS factors, political party identification was associated only with perceptions of the COVID-19 vaccine (<i>P</i> < .001). Associations between political party identification and FASS factors varied by vaccine type. Perceiving science as beneficial was the factor most consistently associated with vaccine evaluations. <b>Conclusions.</b> Republicans are more concerned about the safety and effectiveness of vaccines, with politicization most evident for the COVID-19 vaccine. <b>Public Health Implications.</b> These findings can guide tailored communication strategies addressing vaccine safety and effectiveness concerns among specific audiences. (<i>Am J Public Health</i>. Published online ahead of print September 10, 2026:e1-e9. https://doi.org/10.2105/AJPH.2026.308606).