Dynamic analysis of a varying-strain sveir transmission model

The impacts of strain evolution on transmission dynamics are important for the public and the policymakers during the spread of infectious diseases. A varying-strain model is proposed to analyze the small-scale and short-duration epidemics. First, the expression of basic reproduction number is obtained by next generation matrix method. Then, the stabilities of equilibrium points are derived by Routh–Hurwitz criterion and LaSalle’s invariant principle. Further, combining the official surveillance data, the impacts of infection scales are investigated. Meanwhile, the sensitivity analysis for basic reproduction number and peaks of infected individuals are conducted. The results of this study provide significant insights for the policymakers controlling small-scale and short-duration epidemics.