Abstract
Highlighted by the G7 Hiroshima Summit and evident in Japan's complex vaccination program, the issue of novel coronavirus disease 2019 (COVID-19) vaccine allocation and utilization, particularly the dilemma of minimizing vaccine wastage, extends beyond national concerns. Various global strategies, such as using behavioral science principles like 'nudges', have been implemented to tackle the problem. However, scientific evaluation and international collaboration are insufficient; thus, analyzing successful case studies and innovative methods is crucial to pave the way for future preparedness and resilient responses to emerging pandemics.