What is it about?

The Coming-of-Age Day ("Seijin-no-hi") and Ceremony ("Seijin-shiki") had a substantial impact on increasing viral transmission among the 20-year-old age cohort, regardless of the epidemic trend or population size.

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Why is it important?

Given our results quantifying the increased risk of infections, discussions are needed on how the ceremony should be conducted during the COVID-19 pandemic and how infection can be avoided, rather than canceling the event. Furthermore, when planning large social events in the future, it is important to be aware of the unique risks associated with these gatherings and effectively communicate such information to the relevant persons and communities.


With the pandemic lingering, it is not realistic to continue to cancel this traditional event. Instead, we should continue to look for measures and risk communication that can reduce the risk of infection. Also, it is necessary for each person participating to be aware of the risk and to make feasible behavioral changes, such as avoiding contact with people at high risk of severe after participating in the event.

Yura Ko
Tohoku Daigaku

Read the Original

This page is a summary of: Impact of the Coming‐of‐Age Day and ceremony on the risk of SARS‐CoV‐2 transmission in Japan: A natural‐experimental study based on national surveillance data, Influenza and Other Respiratory Viruses, July 2022, Wiley,
DOI: 10.1111/irv.13027.
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