HPV Vaccine Communication Strategies: Three-Arm RCT Using Behavioural Insights in Tuscany, Italy

Abstract Introduction In Italy, HPV vaccination coverage remains below the 95% target set by the National Vaccine Prevention Plan across all regions and sexes. Education and effective communication are essential to improve vaccine acceptance among adolescents. This study evaluated the effectiveness of different communication strategies-scientific information or techniques countering cognitive bias-on three outcomes in high school students: knowledge about HPV, vaccine hesitancy (VH), and propensity to attend sexual and reproductive health services (SRHS). Methods A 3-arm randomised controlled trial was conducted. High school classes were randomly assigned to control (no active communication), informative (Instagram page with scientific content), or bias (same content using techniques to counter present bias, information avoidance [IA], and gain-loss framing). All students completed a baseline (T1) and follow-up questionnaire (T2) after 3 weeks. Outcome variations were analysed with a difference-in-difference approach, adjusting for age, gender, and baseline values, considering class-level clustering. Differences by IA level were explored. Results Of 527 students at T1, 334 were included in the final analysis (mean age: 15.2 years; 74% female). At baseline, HPV knowledge was low (mean: 0.27), VH moderate (mean: 0.4), and 48% were likely to attend SRHS. No significant changes in knowledge or VH were observed overall. However, among students with low IA, the information group showed a significant VH reduction vs. control (-0.0798, p = 0.0052); among those with high IA, the effect reversed (+0.2572, p = 0.0003). The propensity to attend SRHS increased in the information group (+0.682 vs. control, p = 0.21) among students with low IA. Conclusions The findings stress the importance of tailoring communication to target audiences. Scientific information reduced VH only among adolescents with low IA, highlighting the need for differentiated strategies to increase vaccine uptake. Key messages • Integrating behavioural insights into vaccination campaigns can enhance relevance and impact among adolescent populations, especially when tailored to their cognitive and emotional profiles. • Information avoidance plays a key role in mediating adolescents’ responses to health communication and should be considered when designing strategies to reduce vaccine hesitancy.