Effects of Scalable, Wordless, Short, Animated Storytelling Videos on Flu Vaccine Hesitancy in China: Nationwide, Single-Blind, Parallel-Group, Randomized Controlled Trial.

Background: Low influenza vaccination rates in China pose a serious public health threat. The vaccination prevents infection, but widespread vaccine hesitancy remains a significant barrier. Short, animated storytelling videos may help by conveying health messages in an engaging, culturally neutral format that transcends literacy barriers. Objective: We aim to investigate whether scalable, short, animated storytelling videos, using different storytelling techniques-humor, analogy, and emotion-could reduce influenza vaccine hesitancy among Chinese adults. Methods: In this single-blind, parallel-group, randomized controlled trial, we recruited adults in China through quota sampling. Participants were randomly assigned to 1 of 3 short, animated storytelling video intervention groups, each using a different storytelling technique (humor, analogy, or emotion) or a control group in a 1:1:1:1 ratio. After watching the video or being assigned to the control group, participants completed the questionnaire. Influenza vaccine hesitancy was compared between each intervention group and the control group, respectively, as well as between different intervention groups, with P values adjusted for multiple comparisons. Results: A total of 12,000 participants met the inclusion criteria. Participants in any scalable animated storytelling video group showed lower hesitancy than controls (mean difference -0.41, 95% CI -0.60 to -0.23; P<.001). Specifically, both intervention groups with humor (video A) and analogy (video B) storytelling techniques resulted in significantly lower hesitancy compared to the control group, with mean differences of -0.44 (99.17% CI -0.75 to -0.13; P<.001) for video A and -0.55 (99.17% CI -0.86 to -0.24; P<.001) for video B. However, the intervention group with emotion video (video C) did not show significant effects compared to the control group, nor were there significant differences compared with the other 2 intervention groups. In subgroup analyses, video A effectively reduced vaccine hesitancy among urban residents and participants from southern and southwestern China. Video B was effective within participants aged 40-49 years, both sexes, both urban and rural residents, those with a college education or higher, households with an income of CN ¥90,000-180,000 (the 2021 official exchange rate of CN ¥1=US $0.155 was used for reference, based on World Bank data), and participants from the southwestern region and the western economic belt. Conclusions: Our study showed that storytelling videos, especially with humor and analogy, reduced hesitancy among Chinese adults. Our results highlight the importance of selecting appropriate narrative strategies for health communication, particularly for vaccine hesitancy across various demographic and regional contexts. Given the scalability, low cost, and high accessibility of short, animated storytelling videos, integrating them into national health campaigns could enhance vaccine uptake and mitigate hesitancy in underserved populations. Future research should explore the long-term impacts of these interventions on vaccine uptake and their adaptability to other preventive health measures.