Evolution of Perceived Vulnerability to Infection in Japan During the COVID-19 Pandemic

The global pandemic triggered by the emergence of the highly contagious disease known as COVID-19 has brought about substantial shifts in the everyday lives of individuals across the globe. The present study aimed to elucidate the evolution of perceived vulnerability to disease (PVD) before, during, and after the pandemic by comparing PVD levels in Japan from 2018 to 2023. We analyzed longitudinal changes in perceived vulnerability to disease (PVD) using data collected in Japan across five time points (2018, 2020, 2021, 2022, and 2023). Data from 2018, 2020, and 2021 were obtained from publicly available datasets, while we collected data from 2022 and 2023 for this study. The results showed that although PVD (consisting of perceived infectability and germ aversion) increased significantly in the early stages of the pandemic in 2020, it decreased each year thereafter. By 2023, perceived infectability had declined to a level lower than in 2018, while germ aversion, although lower than in 2020, remained higher than pre-pandemic levels. This finding indicates a tendency to negative estimate one's resistance to infection during the pandemic, while after the crisis abated, individuals tend to assess their resistance to infection more positively. In contrast, germ aversion continued to show a lasting effect, remaining elevated even three years after the peak. These results suggest that the pandemic may have introduced a dual effect: in addition to heightening sensitivity to infection prevention, it may have cultivated a sense of “overconfidence” regarding infection resistance. This overconfidence potentially contributes to a more relaxed attitude toward infectious disease risks, as individuals perceive themselves as resilient after enduring an unprecedented public health crisis.