# Evolution of the public opinion on COVID-19 vaccination in Japan

**Authors:** Yuri Nakayama, Yuka Takedomi, Towa Suda, Takeaki Uno, Takako Hashimoto, Masashi Toyoda, Naoki Yoshinaga, Masaru Kitsuregawa, Luis E. C. Rocha, Ryota Kobayashi  
**arXiv:** [2207.10924](https://arxiv.org/abs/2207.10924)  
**Date:** 2022-07-22  
**Summary page:** https://www.summarizepaper.com/en/paper/2207.10924v1/

## Key points

- Study focuses on the evolution of public opinion regarding COVID-19 vaccination in Japan
- Over 100 million vaccine-related tweets collected from 8 million users
- Latent Dirichlet Allocation model used for automated topic modeling
- 15 topics identified, grouped into four themes: Personal issue, Breaking news, Politics, and Conspiracy and humour
- Shift in public opinion over time: initially focused on personal issues and acquiring knowledge from news, criticism of government's handling of vaccination campaign; later shifted towards sharing personal experiences
- Interrupted time series regression analysis conducted to examine impact of critical events on public opinion
- Tokyo Olympic Games had significant effect on public opinion but did not influence vaccination campaign
- Various events affected public opinion on politics positively early on but negatively later
- Tweets about personal issues more likely to be retweeted when targeting younger populations during vaccination campaign
- Public engagement through social platforms played crucial role in speeding up vaccine uptake by reducing anxiety through social learning and support
- Governments should engage with citizens through social media to allow sharing of experiences and learning from each other's stories

## Summary

The study focuses on the evolution of public opinion regarding COVID-19 vaccination in Japan. The researchers collected over 100 million vaccine-related tweets from 8 million users and used the Latent Dirichlet Allocation model to perform automated topic modeling. They identified 15 topics grouped into four themes: Personal issue, Breaking news, Politics, and Conspiracy and humour. The analysis revealed a shift in public opinion over time. Initially, there was attention towards personal issues and acquiring knowledge from the news, as well as criticisms of the government's handling of the vaccination campaign. However, as confidence in the campaign grew, there was a shift towards sharing personal experiences. The researchers also conducted an interrupted time series regression analysis to examine the impact of critical events on public opinion. They found that while the Tokyo Olympic Games had a significant effect on public opinion, it did not influence the course of the vaccination campaign. Various events also affected public opinion on politics positively in the early stages but negatively later. Furthermore, they observed that tweets about personal issues were more likely to be retweeted when targeting younger populations during the vaccination campaign. Overall, these findings suggest that public engagement through social platforms played a crucial role in speeding up vaccine uptake by reducing anxiety through social learning and support. This highlights how important it is for governments to engage with citizens through social media when launching campaigns like this one so that people can share their experiences and learn from each other's stories.