Abstract
In this report we propose a modelling framework to analyse and optimise worldwide vaccine allocation strategies, with reference to the current COVID-19 pandemic. We model epidemiological transmission and vaccination in a system of M interacting countries, quantifying the social and economic costs incurred by each country due to the pandemic and the country's vaccination rate. Under constraints over global vaccine availability, we analyse best strategies of vaccine allocation: either with the aim of minimising global costs, or by taking the perspective of a competitive game where each country aims to minimise its own cost. We distinguish between the financial capabilities of different countries, and extend our framework to allow for vaccine donation from wealthier to poorer countries. Numerical simulations allow us to compare the best strategies of the above two approaches, and to analyse circumstances under which vaccine donation simultaneously benefits both donating and receiving countries.