AUTHOR=Zhu Wenhui , Feng Jie , Li Cheng , Wang Huimin , Zhong Yang , Zhou Lijun , Zhang Xingyu , Zhang Tao 

TITLE=COVID-19 Risk Assessment for the Tokyo Olympic Games

JOURNAL=Frontiers in Public Health

VOLUME=Volume 9 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2021.730611

DOI=10.3389/fpubh.2021.730611

ISSN=2296-2565

ABSTRACT=Introduction
As of June 7, 2021, the outbreak of Coronavirus Disease 2019 (COVID-19) has spread to more than 200 countries. The global number of reported cases is more than 172.9 million, with more than 3.7 million deaths, and the number of infected individuals is still growing rapidly. Consequently, events and activities around the world were cancelled or postponed, and the preparation for sporting events were greatly challenged. Under such circumstances, about 11,000 athletes from approximately 206 countries are arriving in Tokyo for the 32nd Summer Olympic Games. Therefore, it is urgently necessary to assess the occurrence and spread risk of COVID-19 for the Games.
Objectives
To explore effective prevention and control measures for 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 used Poisson distribution to determine the number of initial infected patients based on the number of countries involved. Furthermore, 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 current COVID-19 prevention measures proposed by the Japan Olympic Committee were needed to be enhanced. And the large-scale vaccination will effectively control the spread of COVID-19. When the protective efficacy of vaccine is 78.1% or 89.8%, if the vaccination rate of athletes reaches 80%, an epidemic prevention barrier can be established.