The World Health Organization lists vaccine hesitancy as one of the top ten global threats to public health. The decision to get vaccinated depends on numerous factors, including health literacy. Health literacy refers to the ability to obtain, understand, and use fundamental health information and services, enabling individuals to make appropriate health decisions. Despite health literacy’s crucial role in health behaviors and outcomes, previous research has produced inconsistent results regarding its influence on vaccination decisions. The project aims to examine the role of health literacy in vaccination decisions by: comparing the effects of health literacy with other vaccination determinants; exploring the potential differential effects of health literacy on vaccination, which may vary across social groups; conducting an experimental study on vaccine characteristics that contribute to vaccination and examining how preferences differ according to health literacy; investigating the relationship between critical health literacy and attitudes towards vaccination; reviewing research on the relationship between health literacy and vaccination; performing a multilevel analysis of determinants influencing vaccination attitudes in Europe; exploring latent profiles (groups of) people based on their vaccination attitudes.