Aşı karşıtı bir anket ile Türkiye'de Covid-19 aşısı talep ve arz planlaması

The Covid-19 virus, which affects many people, continues in a very contagious state. Vaccination is necessary to end this pandemic period, which everyone wants to end as soon as possible. The studies in the literature focuses on different phases of the vaccination such as product, production, allocation or distribution. Existing, expected and sudden outbreaks are studied considering developed and developing countries. But many studies focus on expected outbreaks in developed countries. There are, however, a limited number of studies for sudden outbreaks because of the uncertainties. Therefore, in this study, we focus on Covid-19, which is a sudden outbreak, and the study is executed in a developing country, Turkey. As the attitude towards vaccination might differ across subpopulations, vaccine hesitancy might affect all of purchasing, distribution, and allocation decisions of vaccines. We conduct a survey in order to reduce the uncertainties about the vaccine demand. We analyze on vaccine selections, government decisions about the purchase of the vaccines, vaccination groups and create a supply chain plan. Covid-19 affects us in a very harmful way and there are several issues we can consider in order to come up with an efficient vaccination plan. Since the vaccine demand is the key factor that affects our decisions, we have to forecast the demand with the least error we can get. If the predicted demand is higher than the actual demand, we would purchase vaccines more than we need and we have to deal with wastage and purchasing costs. If the predicted demand is less than the actual demand, we would miss the opportunity to vaccinate more people and get closer to the end of the pandemic. Thus, by predicting the demand in an accurate way, we can make more meaningful decisions in our supply chain. In our survey, we try to understand the thoughts of individuals in Turkey by asking questions about side effects of vaccines, the acceptance of vaccines, the distrust of the number of cases and deaths announced. The responses help us predict the vaccine demand. After forecasting the weekly demand, we use them in our optimization model to construct a weekly vaccine supply plan for Turkey over a one-year planning horizon. The goal of the optimization model is to minimize the total costs of purchasing, transportation, storage, backordering and to reach the herd immunity. In this model, we consider storage and transportation capacity limits, minimum required vaccination rate to reach the herd immunity, and vaccine demand satisfaction with respect to priorities of the cities.