Popular attitudes toward vaccination in the post-COVID-19 period: a social media analysis

The COVID-19 pandemic triggered unprecedented global vaccination campaigns while simultaneously fueling misinformation and vaccine hesitancy. This study analyzed 77,171 English-language tweets related to vaccination collected between December 2020 and May 2021 to understand how attitudes toward vaccination evolved during this critical period and may persist into the post-pandemic era. Employing a mixed-methods approach combining sentiment analysis, thematic classification, and demographic analysis, we identified concerning trends that could affect vaccination acceptance beyond COVID-19. Results revealed a significant decline in positive sentiment (18.3–10.9%) and increase in negative sentiment (9.1–14.6%) over the study period, with a critical inflection point occurring in February 2021. Trust in institutions emerged as the most frequently discussed theme, with initially strong positive sentiment that decreased considerably by May 2021. Childhood vaccination demonstrated a dramatic increase in negative sentiment, rising from 6.7–43.3% by April 2021. Furthermore, users with larger follower counts were found to contribute more negative content, amplifying skepticism. The study identified eight key misinformation categories, including claims about DNA alteration, government control, and 5G connectivity. Interpreted through the Health Belief Model, Social Amplification of Risk Framework, and Institutional Trust Theory, the findings suggest that vaccine distrust may extend to routine immunizations. The results emphasize the urgency of tailored communication strategies to rebuild public trust in vaccines in the post-pandemic world.