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

TL;DR

This study analyzed over 100 million tweets to track how public opinion on COVID-19 vaccination in Japan evolved, revealing shifts in themes and the impact of major events on public sentiment and engagement.

Contribution

It applied large-scale social media analysis and topic modeling to understand the dynamics of public opinion during Japan's vaccination campaign, highlighting the role of social platforms in vaccine uptake.

Findings

Public opinion shifted from personal concerns to confidence in vaccination.

Major events like the Tokyo Olympics influenced political sentiment.

Social media engagement helped reduce vaccine-related anxiety.

Abstract

Vaccines are promising tools to control the spread of COVID-19. An effective vaccination campaign requires government policies and community engagement, sharing experiences for social support, and voicing concerns to vaccine safety and efficiency. The increasing use of online social platforms allows us to trace large-scale communication and infer public opinion in real-time. We collected more than 100 million vaccine-related tweets posted by 8 million users and used the Latent Dirichlet Allocation model to perform automated topic modeling of tweet texts during the vaccination campaign in Japan. We identified 15 topics grouped into 4 themes on Personal issue, Breaking news, Politics, and Conspiracy and humour. The evolution of the popularity of themes revealed a shift in public opinion, initially sharing the attention over personal issues (individual aspect), collecting information from the news (knowledge acquisition), and government criticisms, towards personal experiences once confidence in the vaccination campaign was established. An interrupted time series regression analysis showed that the Tokyo Olympic Games affected public opinion more than other critical events but not the course of the vaccination. Public opinion on politics was significantly affected by various events, positively shifting the attention in the early stages of the vaccination campaign and negatively later. Tweets about personal issues were mostly retweeted when the vaccination reached the younger population. The associations between the vaccination campaign stages and tweet themes suggest that the public engagement in the social platform contributed to speedup vaccine uptake by reducing anxiety via social learning and support.