Explaining Partisan Polarization in Vaccine Attitudes: Misinformation, Elite Cues, and Opinion Updating

Partisan differences in U.S. vaccine attitudes increased substantially during the 2010s, but the mechanisms behind this divergence remain contested. One explanation emphasizes partisan differences in information processing, while another highlights elite cueing. This preregistered survey experiment uses a quota sample of U.S. adults to test these competing accounts. Respondents were randomly assigned to receive information about a novel vaccine, misinformation about the vaccine, or misinformation followed by corrective information attributed to Democratic or Republican leaders. Misinformation increased perceptions of vaccine harm, but this effect did not differ significantly across partisan groups. Corrective information reduced perceived harm only when delivered by a copartisan source, with similar effects for Democrats and Republicans. These findings suggest that partisan differences in vaccine attitudes stem less from asymmetric information processing than from the cumulative effects of elite messaging. More broadly, they underscore the role of partisan cue-taking in the development of vaccine polarization.