Asymmetric affective polarization regarding COVID-19 vaccination in six European countries.

While recent research has shown that supporters and opponents of COVID-19 vaccination have polarizing political attitudes and beliefs, we lack a thorough understanding of how these two groups think about each other. To investigate the feelings and stereotypes between supporters and opponents of COVID-19 vaccination, this study draws on cross-sectional survey data from six European countries (France, Germany, Italy, Spain, Switzerland, and the United Kingdom), collected between January and March 2022 (n = 6379). Our findings indicate an opinion-based affective polarization between supporters and opponents of COVID-19 vaccination. Both groups not only adopt different positions on the issue but also display dynamics of in-group favoritism and out-group hostility. Most notably, our assessment of thermometer scores and character trait ratings shows that this affective polarization is asymmetric, as it is stronger among the pro-vaccination group. Our findings are critical to the control of infectious diseases because affective polarization has been shown to influence health behaviors such as compliance with government policies. The issue is even more pressing as globalization boosts the threat of pandemic emergence and accelerates the global transmission of diseases.