COVID-19 vaccine hesitancy and suboptimal vaccine uptake rates are pressing public health challenges. Vaccine hesitancy has been observed for different vaccines. For COVID-19 vaccines, multiple factors influence vaccine uptake in the U.S. including political ideology. A more nuanced understanding of the factors influencing COVID-19 vaccine uptake within political parties is needed. This study assesses the relationship between known vaccine hesitancy factors and vaccine uptake within two major political parties. Data from 804 U.S. participants in an online survey from June 2021 was used to assess the association between COVID-19 vaccine uptake (no dose vs. any dose) and categories of factors thought to influence vaccine uptake (sociodemographic variables, COVID-19 disease and vaccine belief variables, belief in COVID-19 prevention behavior variables, and social network features variables) for Republicans and Democrats using bivariate and multivariate regression. 65.4% of the sample reported having received at least one dose of the COVID-19 vaccine (22.6% Republican and 52.1% Democrat). In the total sample bivariate model, Democrat participants had significantly greater odds of having received a dose of the vaccine as compared to Republican participants (OR = 2.51, 95%CI = 1.73-3.64). In adjusted models, the speed of vaccine development was negatively associated with vaccine uptake for both Republicans (aOR = 0.18, 95%CI = 0.06-0.57) and Democrats (aOR = 0.40, 95%CI = 0.19-0.86), as was concern about side effects from the vaccine (Republicans: aOR = 0.15; 95%CI = 0.05-0.47; Democrats: aOR = 0.14, 95%CI = 0.06-0.31). COVID-19 vaccine uptake among Republicans, but not Democrats, was associated with belief that the vaccine prevents COVID-19 (aOR = 3.29, 95%CI = 1.29-8.37) and belief about friends' vaccine intentions (aOR = 6.19, 95%CI = 2.39-16.05). There were no significant factors unique to Democrats. Concerns about aspects of COVID-19 vaccine safety for both political groups suggest that vaccine advocacy interventions should universally address these factors. However, Republican beliefs in vaccine efficacy and in friends' vaccine intentions suggest a need for Republican-specific messaging.
Keywords: COVID-19; Political party; beliefs; politics; prevention behaviors; social norms; vaccine hesitancy; vaccine uptake.