**2. Materials and Methods**

The tool used to conduct the research was a mathematical model, i.e., a system of differential equations representing the transmission dynamics of COVID-19. The mathematical model was obtained through the process of mathematical modeling to convert the transmission mechanisms and problems therein into mathematical concepts and mathematical problems. In this case, the main concepts were a system of differential equations and related problems on how to determine and understand solutions to the problems at hand (the detailed method can be found in [19–21]). The following section presents the mathematical modeling process used for the remaining discussion.
