Effectiveness of information interventions in reducing HPV vaccine hesitancy: a randomized survey experiment in China.

INTRODUCTION: In September 2025 China announced the inclusion of HPV vaccination in its national immunization program; parental hesitancy remains the major modifiable barrier to rapid coverage expansion among school-age girls. Our study assessed the effectiveness of safety-focused, personal benefit, and collective benefit information interventions (vs. basic information alone) on parental HPV vaccine hesitancy. METHODS: This double-blind, parallel-group randomized online survey was conducted in mainland China (November-December 2023). Parents of unvaccinated girls aged 9-14 years were recruited by quota sampling. Parents were screened as slight or high hesitancy by a single screening question and randomized to four groups. All received basic vaccine information, with groups additionally received: none (control), safety-focused, personal benefit, or collective benefit information. HPV vaccine hesitancy (VHS-HPV) was the primary outcome, parental willingness to pay (WTP) the secondary. Intervention effects were analyzed using generalized linear models with multiple-comparison-adjusted P values. RESULTS: A total of 1062 parents were randomized into four parallel groups (control, safety-focused, personal benefit, and collective benefit), with 1002 completing the survey and included in the analysis. Compared with the control group, VHS-HPV scores were significantly lower in groups exposed to the personal benefit message (difference, -0.85; 95 % CI, -1.69 to -0.19; adjusted P = 0.045) and the collective benefit message (difference, -1.08; 95 % CI, -1.89 to -0.27; adjusted P = 0.009). In contrast, no statistically significant difference was observed in the safety message group (-0.36; 95 % CI, -1.23 to 0.50; adjusted P = 0.410). The effects were more pronounced among parents with higher hesitancy, with significant differences of -2.39 (95 % CI, -4.36 to -0.42; adjusted P = 0.018) for the personal benefit group and - 3.02 (95 % CI, -4.96 to -1.08; adjusted P = 0.003) for the collective benefit group compared to the control, while no significant difference was observed for the safety message group in this subgroup (-1.32; 95 % CI, -3.42 to 0.78, adjusted P = 0.219). Moreover, no intervention significantly altered WTP. CONCLUSIONS: In this large online experiment, brief personal or collective benefit messages reduced parental HPV vaccine hesitancy beyond basic information alone, particularly among highly hesitant parents, without affecting WTP. Embedding such messaging into official digital communications could accelerate uptake under China's newly launched national program. TRIAL REGISTRATION: Registered with the China Clinical Trial Registry under registration number ChiCTR2300073106 (Registered on July 1, 2023; Last Refreshed on: 2023-12-17. Available from: https://www.chictr.org.cn/showproj.html?proj=198347).