Objective: Previous literature has indicated a strong negative correlation between the moral foundation of purity/sanctity and vaccination rates. The current research investigated how purity concerns impact COVID-19 vaccination hesitancy and tested an information intervention to bolster vaccination intention among people with purity concerns. Method: Study 1 surveyed 566 Republicans and Republican-leaning Independents in the United States. Study 2 was a between-subject-designed survey experiment that investigated the impact of three statements on the COVID-19 vaccination attitudes and intentions of 637 Republicans and Republican-leaning Independents. Statement 1 argued that vaccines are not impure from a scientific perspective; Statement 2 made the same argument with quotes from the Bible; and Statement 3 was a control statement. Results: Study 1 established a significant correlation between the existence of vaccination history and purity as a moral foundation. Study 2 found that among those with no COVID-19 vaccination history, statements arguing that vaccines are not impure from either a scientific perspective or a religious perspective improved attitudes toward vaccination and intention to get vaccinated. Conclusion: Purity concerns can be leveraged as a way to bolster vaccination rates, especially among conservatives. However, the impurity perception only mediated the causal relationship between the treatment and the attitude toward vaccines (but not the actual intention), suggesting that changes in the actual vaccination behavior are subject to factors other than purity concerns.

Previous literature has indicated that the moral foundation of purity/sanctity correlates strongly with vaccination rates. With two pre-registered studies conducted with Republican and Republican-leaning Independents, the current research investigates how purity concern impacts COVID-19 hesitancy. Study 1 (N = 566) found that the relationship between vaccination history and purity moral foundation is mediated by the perception that vaccines are impure, and such perception is dependent on the belief that the human body is sacred. Study 2 (N = 637) found that among those with no COVID-19 vaccination history, statements arguing that vaccines are not impure from either a scientific perspective or a religious perspective prompted them to believe that getting vaccinated is a better idea and increased their perceived likelihood to get at least one shot of a COVID-19 vaccine during the next six months. However, the impurity perception only mediates the causal relationship between the treatment and the attitude toward vaccines (but not the actual intention), suggesting that changes in the actual vaccination behavior are subject to factors other than purity concerns.