Opinion Leadership and Sharing Positive and Negative Information about Vaccines on Social Media: A Mixed-Methods Approach

"In sum, the findings advance theoretical discussions on the role of opinion leadership in information sharing and offer practical insights into promoting vaccination for children among parents."

While the sharing of vaccine-related information on social media has emerged as a public health concern, the dissemination of facts about vaccination and its benefits can increase awareness about vaccination and improve vaccination rates. The central figures in such information sharing, called "opinion leaders",” are often recognised for their connectivity, their willingness to offer others expertise (their "maven"), and their persuasiveness. Conducted among parents in Hong Kong, the research described in this article examines how different dimensions of opinion leadership are associated with sharing positive and negative information about vaccines on social media.

For Study 1, the researchers collected data from Baby Kingdom, the largest online forum for parents and expectant parents in Hong Kong. Using negative binomial regression, they examined the effects of connectivity, maven, and persuasiveness on two dependent variables: the number of positive and negative comments about vaccines posted by each user.

In terms of sharing positive information about vaccines, the effects of connectivity were significant. In particular, users' degree centrality was significantly associated with the number of positive posts shared. In terms of maven, topic engagement and topic impact were significantly and positively associated with sharing positive information. Finally, persuasiveness was not significantly associated with the number of positive posts.

For Study 2, using Qualtrics online panels, the researchers recruited 587 permanent residents of Hong Kong who had at least one child aged 2-11 years old to participate in self-assessment using survey data. They conducted two hierarchical regression analyses, with parents' intention to share positive information (i.e., Model 1) and negative information (i.e., Model 2) about COVID-19 vaccines for children on social media as the respective dependent variables. The results showed that, in terms of the intention to share positive information on social media, two dimensions of parents' self-perceived opinion leadership-connectivity and maven were positively associated with the intention to share information. Concerning the intention to share negative information on social media, all three dimensions of self-perceived opinion leadership were positively associated.

Thus, although the outcome variables in the two studies differed slightly - information-sharing behaviour in Study 1 and information-sharing intention in Study 2 - the findings from the two studies were largely consistent. In particular, whereas connectivity and maven were significantly associated with sharing positive information about vaccines, all three dimensions were significantly associated with sharing negative information about vaccines. Those results underscore the importance of persuasiveness in sharing negative information about vaccines.

The researchers explain that sharing negative information about vaccines and/or vaccination for children means sharing information opposed to the recommendations of health authorities. Thus, in other words, the "results indicate that what matters might not be the valence of the information shared but the extent to which the shared information is consistent with the recommendations of authorities. It is plausible that sharing information that diverges from those recommendations demands stronger, more comprehensive opinion leadership than sharing information endorsed by the government and/or health authorities. However, such speculation needs further investigation, especially in other contexts."

Based on the findings, the researchers recommend that public health professionals prioritise regular engagement with opinion leaders, focusing not only on enhancing their knowledge about infectious diseases and vaccination but also on equipping them with strategies for reciprocal interactions during health campaigns.

"Given that the early stages of an outbreak are often marked by uncertainty and confusion, these well-informed and reciprocally engaged opinion leaders can play a crucial role in delivering accurate information to the public."