Overcoming the Triple Challenges of Digital Contact Tracing in Japan

During the recent COVID-19 pandemic, various countries developed and deployed digital contact tracing tools as game-changers for infection control. As the pandemic approaches its final stages, evaluations of these efforts are progressing in different countries. This paper examined COCOA, a contact tracing app developed in Japan, to identify the reasons for its failure to function effectively. To address these issues, we proposed a solution that leverages technologies studied in Japan prior to the pandemic, and introduced an ongoing study at campus-level to demonstrate their potential. Digital contact tracing represents a significant technological innovation in public health, and it is desirable to expand the scope of validation to regional and national levels, in the future, for further development.