COVID-19 risk assessment for the Tokyo Olympic Games

Abstract Objectives To explore effective prevention and control measures for Coronavirus Disease 2019 (COVID-19) in large international events through simulations of different interventions according to risk assessment. Methods We used random model to calculate the number of initial infected patients. And Poisson distribution was used to determine the number of initial infected patients based on the number of countries involved. Further, to simulate the COVID-19 transmission, the susceptible-exposed-symptomatic-asymptomatic-recovered-hospitalized (SEIARH) model was established based on susceptible-exposed-infectious-recovered (SEIR) mathematical model of epidemic diseases. According to risk assessment indicators produced by different scenarios of the simulated interventions, the risk of COVID-19 transmission in Tokyo Olympic Games was assessed. Results The large-scale vaccination will effectively control the spread of COVID-19. If the effective rate of vaccine is 100%, and the vaccination rate of athletes reaches 80%, an epidemic prevention barrier can be established. Conclusions The current COVID-19 prevention measures proposed by the Japan Olympic Committee were needed to be enhanced. For the vaccination intervention had the best control effect, a mass vaccination serves was an effective way to control COVID-19. Keywords: COVID-19; SEIARH model; interventions; Tokyo Olympic Games; risk assessment