Pieter de Boer works as a health economist in the Modelling of Infectious Diseases unit. As health budgets are limited, decisions should be made on whether or not to reimburse a health intervention like vaccination programmes. Cost-effectiveness analyses help decision makers to get insight in the costs and benefits of such interventions, and to relate these to the corresponding health gains. In this way, the efficiency of different interventions can be compared, and the health gains can be maximized.Pieter models the impact of preventive programmes on the number of infections, hospitalizations and deaths, with corresponding cost-effectiveness and uncertainty analyses. In recent projects, Pieter worked on the cost-effectiveness of influenza vaccination, screening for chronic Q-fever and shingles vaccination.