Instagram influencers in health communication: Examining the roles of influencer type and message construal in COVID-19 prevention public service announcements

While public health authorities have increasingly leveraged social media influencers to advocate preventive health behaviors, limited research has evaluated social media influencers’ persuasiveness beyond advertising campaigns. Hence, this study assessed how Instagram influencers shape consumers’ attitudes and behavioral intentions regarding COVID-19 prevention. In total, 239 participants partook in a 2(Influencer type: mega-influencer vs. nano- influencer) x 3(Message construal: independent vs. interdependent vs. collective) between- subjects, factorial experiment. Although participants perceived mega- and nano-influencers to possess similar expertise, trustworthiness, and attractiveness, participants regarded nano- influencers to possess greater homophily than mega-influencers. Additionally, participants evaluated social media influencer endorsements with collective construal more favorably than those with independent construal. Participants exposed to the nano-influencer’s endorsement displayed greater intent to engage in COVID-19 prevention behaviors relative to mega- influencers. Participants’ perceived homophily with the nano-influencer also mediated its effect on participants’ attitudes and behavioral intentions. Theoretical contributions, practical implications, and directions for future research are provided.