University of Seoul, Seoul, South Korea.
Division of Infectious Diseases, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, South Korea.
Sci Rep. 2023 Jun 24;13(1):10261. doi: 10.1038/s41598-023-37498-y.
To achieve endemic phases, repeated vaccinations are necessary. However, individuals may grapple with whether to get vaccinated due to potential side effects. When an individual is already immune due to previous infections or vaccinations, the perceived risk from vaccination is often less than the risk of infection. Yet, repeated rounds of vaccination can lead to avoidance, impeding the establishment of endemic phases. We explore this phenomenon using an individual-based Monte Carlo simulation, validating our findings with game theory. The Nash equilibrium encapsulates individuals' non-cooperative behavior, while the system's optimal value represents the societal benefits of altruistic cooperation. We define the difference between these as the price of anarchy. Our simulations reveal that the price of anarchy must fall below a threshold of 12.47 for endemic phases to be achieved in a steady state. This suggests that for a basic reproduction number of 10, a consistent vaccination rate greater than 89% is required. These findings offer new insights into vaccination-related decision-making and can inform effective strategies to tackle infectious diseases.
要实现地方性流行阶段，需要进行反复接种。然而，由于潜在的副作用，个体可能会对是否接种犹豫不决。当个体由于先前的感染或接种而已经具有免疫力时，接种的感知风险通常低于感染的风险。然而，反复接种会导致回避，阻碍地方性流行阶段的建立。我们使用基于个体的蒙特卡罗模拟来探索这一现象，并通过博弈论验证我们的发现。纳什均衡包含了个体的非合作行为，而系统的最优值代表了利他合作的社会效益。我们将这些差异定义为无政府状态的代价。我们的模拟表明，无政府状态的代价必须低于 12.47，才能在稳定状态下实现地方性流行阶段。这表明，对于基本再生数为 10，需要保持大于 89%的一致接种率。这些发现为与接种相关的决策提供了新的见解，并为应对传染病提供了有效的策略。
