Implications of vaccine shopping during pandemic
研究政策制定者是否应允许个人选择疫苗，以及如何优化单剂和双剂疫苗的采购组合，发现限制选择在供应低时增加接种量，但允许中等犹豫者选择可减少浪费，且提供选择在美国可减少感染。
Many individuals have strong preferences regarding COVID‐19 vaccines and would like to choose the vaccine they get. This practice, known as “vaccine shopping,” presents unique challenges to timely vaccine rollout: On the one hand, people may not get vaccinated if they are unable to receive their preferred vaccine, and on the other hand, a policy maker is inclined to distribute vaccines in a brand agnostic fashion to avoid wastage. We study whether a policy maker should allow individuals to choose their vaccine, and the optimal mix of single‐ and two‐dose vaccines to procure. We develop a stylized queueing game‐theoretic model that captures the main trade‐offs in the interaction between individuals and a policy maker to examine the impact of vaccine choice on the number of vaccinations. Individuals obtain a reward from the vaccine administered at a server and decide whether to get a vaccine based on the wait time, their inclination toward vaccinating, and the level of choice provided. We find that restricting choice results in a greater number of vaccinations when vaccine supply is low by administering doses as and when they become available. Contrary to popular belief that restricting choice wastes fewer vaccines, we find that fewer vaccines are wasted when patients who are moderately hesitant about vaccinating are allowed to choose their vaccine. In this case the possibility of being assigned a nonpreferred vaccine leads patients to forego vaccination, and allowing a choice alleviates this concern. Using a mathematical model for COVID‐19 transmission, we find that providing choice results in fewer infections in the United States than limiting choice, and the number of infections is lowest when a lower efficacy, single‐dose vaccine forms 5%–8% of the total vaccine dose supply. Our findings provide guidance to policy makers, especially as they plan to vaccinate effectively using a diverse vaccine supply.