The Novel Coronavirus (hereafter referred to as COVID-19) continues to have an enormous impact on the socioeconomics both in Japan and in countries around the world. As of December 23, 2022, the cumulative number of confirmed cases worldwide was approximately 652 million, and in Japan the figure was approximately 28 million. In the first wave in 2020, the proportion of those infected was high among those aged 70 and over, but since then it has been declining due to progress in vaccination and other measures (National Institute of Infectious Diseases (2022)). After the second wave, the ratio of infected persons was high among young people in their teens to thirties, and the sixth wave in 2021 showed a relative increase in the age group of 19 years and younger, who were not eligible for vaccination. Although there is an impression that more people are infected in the senior age group because hospitals and elderly care facilities were often reported as the location of cluster outbreaks, the cumulative number of reported cases from late March 2020 to mid-June 2022 shows that infection is more common among the younger generation who are socially active.