S1 Appendix -

<div><p>COVID-19 prevention measures and vaccine policies have led to substantial polarization across the world. I investigate whether and how vaccination status and vaccination status identification affect the sympathy and prejudice for vaccinated and unvaccinated individuals. Drawing on a preregistered vignette survey experiment in a large representative sample from Germany (n = 6,100) in December 2021, I show that prejudice was greater among the vaccinated towards the unvaccinated than vice versa. Furthermore, I find that differences in sympathy ratings are strongly subject to vaccination status identification. If individuals do not identify with their vaccination status, there are no differences in the evaluation of the in- and outgroups. Stronger vaccination status identification is, however, associated with greater prejudice among the vaccinated towards the unvaccinated but not for the unvaccinated towards the vaccinated. The results therefore show a stronger polarization on the side of the vaccinated that increases with the identification of one’s vaccination status.</p></div>