Rising vaccine hesitancy in a future pandemic after COVID-19 and its decision drivers in Japan

Vaccine hesitancy emerged as a major challenge during the COVID-19 pandemic and has persisted beyond it, raising concerns about public readiness for vaccination in future pandemics. While extensive research has examined vaccine hesitancy for COVID-19 and routine immunization, it is unknown how the general population would respond to vaccination in a future pandemic, and what conditions might facilitate acceptance. Here, we analyzed data from a nationwide internet-based survey conducted in Japan between December 2024 and January 2025, involving 28,000 participants aged 15-84 years. We assessed intentions to receive vaccination in a hypothetical future pandemic under varying assumptions regarding disease fatality and vaccine immunity durability. Associations between vaccination intention and sociodemographic, psychological, health-related, informational, and infectious disease-related factors were examined. We further explored priority conditions that could increase vaccination intention. We found that only 53.1% of respondents indicated willingness to be vaccinated in a future pandemic with a case fatality rate comparable to COVID-19, representing a marked decline from observed COVID-19 vaccination coverage. Notably, 35.8% of individuals who had vaccinated during the COVID-19 pandemic reported hesitancy toward vaccination in a future pandemic. Higher assumed fatality rates and longer vaccine protection modestly increased willingness, particularly among those with ambivalent attitudes. Vaccination intention was lower among adults aged 20-40 years, women, individuals with lower income or education, and those endorsing misinformation or conspiracy beliefs, while higher infectious disease knowledge, greater fear of COVID-19, and active information seeking were associated with greater willingness. Clustering analysis identified eight distinct groups with heterogeneous priority structures. Free vaccination and clinical trial evidence were universally valued, whereas trust in authorities, domestic vaccine production, and convenience varied substantially across clusters. Public willingness to vaccinate in a future pandemic may be substantially lower than during COVID-19 and is shaped by diverse priorities. Tailored strategies and risk communication approaches that address heterogeneous concerns may be critical for strengthening preparedness for future pandemics.