Media Exposure and Its Association With Vaccine Attitudes, Intentions, and Hesitancy: Systematic Review

Background: Vaccine hesitancy, amplified by the COVID-19 “infodemic,” has emerged as a pressing public health challenge. Communication strategies are pivotal for enhancing vaccine literacy, countering misinformation, and sustaining immunization programs. Objective: This systematic review evaluates the association between communication channels and vaccine hesitancy and adherence, while examining the moderating role of sociodemographic factors. Methods: A PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)–compliant search was conducted across PubMed, Scopus, and Web of Science, yielding 17,407 records screened according to predefined eligibility criteria (peer-reviewed studies with N>1000 adults assessing communication media targeting vaccine hesitancy and adherence, excluding pediatric, health care–specific, and non-English research). After full-text assessment, studies were appraised using the Modified Medical Education Research Study Quality Instrument for methodological quality and the Joanna Briggs Institute Critical Appraisal Checklist, ROBIN-I (Risk of Bias in Nonrandomized Studies of Interventions), or RoB 2.0 (Risk-of-Bias 2.0 tool for randomized trials) tools for risk of bias. Results: Thirty-six studies were included (26 cross-sectional, 4 quasi-experimental, 4 randomized controlled trials, 1 cohort, and 1 global analysis). Randomized and nonrandomized experimental studies demonstrated that tailored communication strategies delivered via radio, web platforms, and social media significantly improved vaccine acceptance. Adaptive public health campaigns achieved up to an 8% weekly increase in uptake in Madagascar (relative risk 1.08; 95% CI 1.01-1.15) and a 7.8% higher vaccination rate among Nigerian adults at first follow-up compared with controls. Digital and social media campaigns effectively reduced hesitancy and enhanced trust among hesitant pregnant women in the United States. Sociodemographic factors significantly moderated communication outcomes: a COVID-19 chatbot proved most effective among individuals with lower education and minority backgrounds, while religiosity (b=0.17; 95% CI 0.05-0.30; t810=2.80; P=.005) and cultural congruence (odds ratio 1.89; P<.01) influenced message credibility and engagement, respectively. The persuasive effect of online memes on COVID-19 vaccine intentions was not significantly influenced by gender (P=.83), age (P=.60), or political orientation (P=.44). Age-specific effects were observed, with greater responsiveness to a social media campaign among adults aged 25-34 years and reduced hesitancy among older groups. Multiple cross-sectional studies indicated higher adherence among audiences exposed to traditional media (television, radio, newspapers) and lower trust among social media users. Other studies suggested significant influences of gender, age, socioeconomic status, education level, and political orientation. Conclusions: By synthesizing fragmented evidence, this review provides a systematic examination of the interplay between multichannel media and vaccine acceptance. It diverges from existing literature by integrating both traditional and digital media perspectives through the lens of sociodemographic moderation. This work offers a critical framework for public health interventions, advocating for rigorous longitudinal research to establish definitive causal links between communication and behavior. Consequently, these findings support a “precision” communication model, enabling the development of culturally congruent strategies tailored to specific recipient profiles to bolster vaccine adherence. Clinical Trial: PROSPERO CRD42025637441; https://tinyurl.com/4r9w83kw