The Washington Post quoted Research Director Kenji Shibuya as saying that the recent decrease in COVID-19 cases in Japan suggests that the “virus may be moving in a cyclical pattern of a roughly two-month period of peaking and ebbing.”

The epidemiology expert pointed out that even without a full, draconian lockdown in Japan, people were very stringent “about wearing masks and social distancing.” Shibuya noted that the severity of the pandemic in each country may hinge on the “very complicated interactional role” of seasonal, human, and viral factors.

The decrease in Japan, he added, might be due to unknown characteristic about the virus, given that “social interactions never quite stopped” in Japan. “We need to look into the endemic phase of covid now,” he said.

“Japan and South Korea Never Did Full Lockdowns. It Left Lessons on How to Coexist with the Virus.” Washington Post
https://www.washingtonpost.com/world/asia_pacific/coronavirus-japan-south-korea-covid/2021/10/20/77a3273c-2d11-11ec-b17d-985c186de338_story.html

Profile of Research Director Kenji Shibuya
https://www.tkfd.or.jp/en/experts/detail.php?id=653