Vaccine disclosure and vaccine hesitancy on social Q&A: comparing topical differences and user engagement in COVID-19 vs non-COVID-19 vaccine questions

Purpose Vaccine hesitancy has become a critical public health challenge, particularly during the COVID-19 pandemic, amplified by social media facilitating the spread of unverified claims. This study compares COVID-19 and non-COVID-19 vaccine questions posed on a leading USA health Q&A community, examining topical differences, user engagement and themes underlying vaccine hesitancy. Design/methodology/approach Questions from Medical Sciences Stack Exchange were collected and pre-processed to identify vaccine-related queries. The analysis included 324 COVID-19 vaccine questions and 187 non-COVID-19 vaccine questions for topical differences. Vaccine hesitancy was examined in 75 COVID-19 and 44 non-COVID-19 vaccine questions. User engagement metrics were compared between the two categories. Findings The study revealed distinct thematic concerns in COVID-19 versus non-COVID-19 vaccine questions, alongside substantial differences in user engagement metrics. Common strategies to address vaccine hesitancy may not be equally effective during public health crises. COVID-19 vaccine hesitancy primarily stemmed from concerns about rapid development, new biotechnologies and the benefits of post-infection vaccination. Non-COVID-19 vaccine hesitancy focused more on the safety of childhood immunization, manufacturing processes, allergy risks and vaccine-related disease myths. The high popularity but low answer acceptance rate of COVID-19 vaccine questions indicated a substantial unmet information need in addressing hesitancies. Originality/value This study compares user concerns regarding established vaccines and those developed during a health crisis, focusing on factors contributing to vaccine hesitancy. It evaluates the extent to which these concerns are addressed on a health Q&A platform, offering insights into information needs and gaps in public understanding of vaccines during routine and emergency health scenarios.