Prioritization of COVID-19 vaccines is one of the most relevant topics in the current pandemic emergency. Prioritization decisions are political decisions that are value-laden, and as such of ethical nature. Despite the clear political and ethical nature of this topic, prioritization decisions are often interpreted and presented as scientific decisions. The aim of this article is twofold. First, we aim to show critical points that characterize certain pandemic vaccination plans from the ethical viewpoint using four dimensions (problem definitions, incorporation of different perspectives, context, and specification). The four dimensions were drawn from findings of the European project "VALIDATE" (VALues In Doing Assessments of healthcare TEchnologies", https://validatehta.eu). Second, we aim to reframe the issue about prioritization itself in the light of the four dimensions mentioned. Our conclusion is that policy-problem definitions, incorporation of different perspectives, contextual considerations and specification of moral principles seem to be common critical points of some vaccination plan documents. The European project "VALIDATE" seems to be able to provide a useful and profitable approach to address many of these critical points.