With the limited initial availability of COVID-19 vaccines in the first months of 2021, decision-makers had to determine the order in which different groups were prioritized. Our aim was to find out what normative approaches to the allocation of scarce preventive resources were embedded in the national COVID-19 vaccination schedules. We systematically reviewed and compared prioritization regulations in 27 members of the European Union, the United Kingdom, and Israel. We differentiated between two types of priority categories: groups that have increased infection fatality rate (IFR) compared to the average for the general population and groups chosen because their members experience increased risk of being infected (ROI). Our findings show a...