A planning model for the WHO-EPI vaccine distribution network in developing countries

In many developing countries, inefficiencies in the supply chain for the World Health Organization's Expanded Program on Immunization (EPI) vaccines are of grave concern; these inefficiencies result in thousands of people not being fully immunized and creates significant risk of disease epidemics. Thus, there is a great deal of interest in these countries in building tools to analyze and optimize how vaccines flow down several levels of the supply chain from manufacturers to vaccine recipients. This article develops a mathematical model for typical vaccine distribution networks in developing countries. This model has been successfully adapted for supply chains in three different countries (Niger, Thailand, and Vietnam), and its application to several issues of interest to public health administrators in developing countries is discussed.