Lessons from COVID-19: Preparedness and Future Challenges for Emerging Infectious Diseases in Japan

Coronavirus disease 2019 (COVID-19) was a major test of Japan's capacity to respond to modern health crises. Despite having one of the world's oldest populations, Japan reported fewer COVID-19 deaths per capita during 2020-2022 than most countries in the Organisation for Economic Co-operation and Development (OECD), although substantial mortality continued after the legal reclassification in May 2023. The pandemic also exposed inflexible care delivery arrangements, the vulnerability of long-term care facilities, fragmented surveillance and research infrastructure, indirect health harms, and shortages and geographic maldistribution of infectious disease professionals. This narrative review summarizes Japan's response and organizes priorities for future infectious disease crises around four interdependent pillars: workforce development; interoperable surveillance, data, and research-and-development capacity; regional collaborative networks built during routine periods; and effective national institutions. Preparedness is best maintained as a layered, continuously evaluated system rather than being assembled after an emergency begins.