Prediction of COVID-19 cases during Tokyo's Olympic and Paralympic Games.

Tokyo's Olympic and Paralympic Games set to begin in late July 2021 without spectators from abroad, but vaccine rollout has been slow in Japan compared with other developed countries. In this study, COVID-19 epidemic curve in Tokyo is developed based on weekly reported data from January 23, 2020, until April 16, 2021. The maximum daily number of infected cases in Tokyo in August 2021 would be 7,991 if the current pace of vaccinations would be used (1/1,000 per day). This daily number is greater than the highest daily cases (2,447) recorded on January 7, 2021. However, if the rollout pace could be doubled (1/500 per day), the peak daily new cases would be 4,470 in August. If it could be quadrupled (1/250 per day), the peak would be noted at 2,128 in July and the highest number in August would be 1,977. If vaccine rollout could not be enhanced, the cancellation might be an acceptable decision, since health is the most precious to local people and our Olympians.