Study Of COVID-19 Model Considering Asymptomatic Infection And Vaccination

Infectious diseases have always been an important threat to human life and health,and the recent global epidemic of novel SARS-Co V-2 infection(COVID-19)is the most damaging infectious disease to people around the world in the last decade.In order to study the transmission dynamics of COVID-19 more scientifically,a mathematical model considering vaccination and asymptomatic infection is designed to study the transmission dynamics of COVID-19.In this paper,we analyzed some basic properties of the model,obtained the expressions for the control reproduction number of the model,gave the conditions for the existence and uniqueness of the endemic equilibrium,analyzed the local stability of the diseasefree equilibrium,the global stability and the local stability of the endemic equilibrium.The model is simulated and analyzed in the context of the spread of COVID-19 in Italy from 2020 to 2021.The numerical and model simulation results suggest that increasing vaccine efficacy can better control the increase in the number of symptomatic COVID-19 infections and that increasing vaccination rates can reduce and delay the peak of infection.However,in reality,improved vaccine efficacy and rapid vaccination cannot be achieved in a short period,and rapid control of COVID-19 cannot be achieved by increasing the vaccination rate alone.Therefore,non-pharmaceutical interventions should continue to be implemented to stifle the continued spread of the virus.Based on the sensitivity analysis of the parameters in the control reproduction number,it can be concluded that,based on the guaranteed vaccination,reducing the population exposure rate will significantly reduce the number of infections and the control reproduction number,stifling the spread of COVID-19.Increasing the rate of isolation of infected patients would increase the number of positive virus tests in the short term,but in the long term,it would significantly reduce the number of infections and decrease the control reproduction number.If the isolation rate of infected patients is low,the control effect of COVID-19 will be weak in the long term.The analysis and simulations in this paper may provide useful suggestions for the prevention and control of COVID-19.