How did internet information influence COVID-19 vaccination? The cyclical influence of the internet information, beliefs, attitudes, and intentions toward vaccines from a three-wave longitudinal study

This study examined the psychological processes leading to the formation of COVID-19 vaccination in Japan, a country with strong vaccine hesitancy, using integrative health behavior theory. We conducted a three-wave longitudinal study of 990 Japanese adults to investigate what information on the internet cyclically influences vaccination attitudes and intentions. The results showed that the psychological process that leads to the acceptance of the COVID-19 vaccine can be explained by applying integrative health behavior theory. However, while susceptibility to and fear of infection significantly influenced vaccination intention at the beginning of the pandemic, only the severity of the disease was significant at Time 3, indicating that the factors that promote vaccination intention can change over time. Nevertheless, subjective norms and self-efficacy were consistently associated with COVID-19 vaccination intentions and beliefs throughout the entire period. Furthermore, although information obtained from the internet influences vaccination intention, this influence varies depending on the content. In particular, information on the availability of vaccines increases vaccination intentions, and vaccination intentions facilitate the viewing of information in the next wave, indicating that information gathering on the internet and vaccine attitudes have a cyclical influence. Although expert information reduced self-efficacy and community benefits in the first wave, this effect decreased over time. The findings provide practical insight into how to increase vaccination intentions in the context of information confusion before and after vaccination programs are launched. • A study of the initial COVID-19 vaccination program in Japan with a high level of vaccine hesitancy. • The internet information and the respondents' attitudes and intentions toward vaccines were cyclical influential. • Information on the availability of vaccines and positive attitudes, self-efficacy, and intention were cyclical enhanced over time. • Expertise information had an initial inhibitory effect on vaccination intention, but the effect eventually weakened. • This study provides practical insights into how to increase vaccine uptake in the face of mixed information.