The issue of COVID-19 vaccine allocation is still highly controversial on the international as well as on the national level, and policy-makers worldwide struggle in striking a fair balance between different ethical principles of vaccine allocation, in particular maximum benefit, reciprocity, social justice and equal respect. Any political decision that implements these principles comes at a cost in terms of loss of lives and of loss of life years that could potentially have been prevented by a different vaccination strategy. This (...) article illustrates these trade-offs using quantitative analysis and shows how this approach can contribute to providing a rational and transparent grounding of political decisions on COVID-19 vaccine allocation. (shrink)