In this article, ‎we examine an allocation issue faced by European Health Union (EHU)‎. ‎Given this situation, ‎we introduce the issue of vaccine selection. ‎The model proposed in this paper helps to implement vaccination optimally using matching theory. ‎By adopting the mechanism presented in this article, ‎this is done more easily and more quickly, ‎so that mortality in society is lower and public satisfaction is increased. ‎This is similar to the issues analyzed in the literature on the design mechanism of non-perishable goods.

By studying game theory, we find that the Nash equilibrium does not exist in some games or, if there is in one, does not describe a real event. Here we show that the matching pennies game with pure strategy has the solution, but this solution is a game that happens simultaneously with this game. Using this solution, we will answer the Brookings Institution's question of boycotting the elections whether the opposition's boycott of elections is, in different circumstances, a defeated strategy. A strategy that its result in most cases is a failure or political suicide and the least possible consequence by the opposition. The findings of this article show that in general, it can be concluded that the election boycott strategy is a dominated strategy, and most of the opposition groups that have used it have failed and they donated the playground to the ruling group.