Abstract

Coronavirus Disease 2019 (COVID-19) booster vaccine uptake has been lower than that of the initial vaccine doses in many countries. Approaches to vaccination vary, with some countries implementing mandatory vaccination and others not. This study aimed to predict COVID-19 booster vaccination intention using Protection Motivation Theory (PMT), coronavirus conspiracy beliefs, social media use, and sociodemographic factors, comparing the United Kingdom (UK), Jordan, Germany, and Austria. A cross-sectional online survey was conducted in the UK, Germany, Austria, and Jordan. Convenience sampling was used to recruit 287 fully vaccinated participants. The survey included items measuring PMT constructs, conspiracy beliefs, social media use, and sociodemographic variables. Data were analysed using bivariate analysis and binary logistic regression. Participants with high booster dose intention showed lower religiosity, conspiracy beliefs, perceived rewards of not getting vaccinated, and perceived costs of getting vaccin