Investigating vaccination behavior and disease dynamics of a time-delayed two-strain epidemic model: An evolutionary approach

The emergence of a new strain during a pandemic, like the present COVID-19, is a serious concern to the healthcare system. The most effective strategy to control this pandemic is vaccination. Many studies suggest that vaccine efficacy against the new strain may reduce. Additionally, the new strain’s late arrival has a significant impact on the disease dynamics and vaccine coverage. Focusing on these issues, this study presents a two-strain epidemic model along with two vaccination provisions based on human behavior dynamics, in which the new strain appears with a time delay. Individuals can commit vaccination before and after being infected with strain 1 and both vaccinated and non-vaccinated individuals can be infected with strain 2. Our findings suggested that delaying the second strain increases the overall vaccination coverage and reduces the peak size of the infected individuals.