RETRACTED: Impact of air transportation on the spread of Covid-19 between countries based on system dynamics (Retracted Article)

For the spread COVID-19 between countries through air transportation, the influencing factors are analyzed, a system dynamics model which passes the validity test is established. Then, three key indicators, Basic Reproduction Rate, Initial Infection Individuals and Transfer Rate, are selected as independent variables to analyze the system changes through computer simulation. Based on the analysis, the infectivity of COVID-19 and the number of people transferred by air transportation are important factors affecting the import of epidemics for non-epidemic countries, and the sooner or later control of infectious diseases by epidemic countries has little effect on non-epidemic countries.