Partisanship, Messaging, and the COVID-19 Vaccine: Evidence From Survey Experiments

To investigate partisanship in COVID-19 attitudes, and assess partisan or scientific messaging effects on COVID-19 vaccination intentions.

Two-wave survey with two-arm randomized experiment.

Recruited Pennsylvania residents online.

2037 (May 2020) and 1577 (October 2020) Pennsylvania residents, aged 18-94 years.

Respondents saw messaging that presented either President Trump or scientists endorsing the vaccine, then reported their vaccination intentions.

Likert scale items measuring COVID-19 attitudes (May), including mask wearing and vaccination intentions (May and October).

Partisan differences in attitudes were analyzed by chi-square; differences in support for mask wearing and vaccination intentions were also analyzed by Mann-Whitney U. The messaging experiment was analyzed by chi-square, Mann-Whitney U, and survey-weighted multivariate logistic regression.

Significant partisan differences were found in all attitudes. The partisan split in support for mask wearing increased from May to October, whereas the split in vaccination intentions decreased. Compared to partisan messaging, scientific messaging increased overall odds of intending to vaccinate by 32% in May (adjusted odds ratio [AOR]=1.32, 95% confidence interval [CI] = 1.06-1.65), and increased odds among Democrats by 142% in October (AOR = 2.42, CI = 1.29-4.55). Scientific messaging had no significant effect on independents or Republicans.

Partisan COVID-19 attitudes were widespread and persistent. Partisan endorsement of the vaccine positively influenced those with congruent beliefs, while scientific messaging produced consistent effects across political affiliation.