Examining the independent and interactive roles of intolerance of uncertainty in vaccination intent

Vaccine hesitancy remains common and sociopolitical anti-vaccine movements continue to gain ground in the United States and beyond. To inform more effective public health campaigns and increase vaccination intent, research is needed on how cognitive and emotional variables interact to influence vaccination intent. Intolerance of uncertainty (IU), defined as experiencing distress or discomfort in response to uncertain situations, is known to influence both approach and avoidance behaviors. IU may interact with other decision-making factors that impact vaccination intent, including people's actual knowledge about disease, perception of disease risk, and worry about vaccine safety. We recruited a community sample of Florida residents (N = 2152) for a longitudinal study spanning the first eight months of the COVID-19 pandemic and tested how COVID-specific IU (i.e., IU pertaining specifically to the disease) independently and interactively influenced vaccination intent. We found that higher COVID-IU early in the pandemic (May/June 2020) significantly predicted greater vaccination intent measured months later (December 2020/January 2021), even after controlling for relevant demographic variables, depression and anxiety symptoms, subjective risk, perceived vaccine safety, and disease knowledge. There was also a significant interaction between IU and knowledge, such that the effect of COVID-IU on vaccination intent was stronger for those with less disease knowledge. These findings suggest that disease specific IU can shape vaccination intent, independently and in interaction with disease knowledge. Our findings suggest that public health messaging seeking to increase vaccine uptake could benefit from emphasizing the distressing nature of the uncertainty inherent in contracting major diseases.