Background and objectives: Vaccination with Human Papillomavirus (HPV) vaccine is recommended for 11-12 years-old, but uptake is suboptimal. Current messaging focuses on HPV infection transmission and prevention. Parents and providers are often uncomfortable discussing sexual practices of adolescents, contributing to the delay/refusal of vaccine. We created a cervical cancer-salient message encouraging HPV vaccination, emphasizing disease salience and disease threat, while promoting self-efficacy. We hypothesized this message would have greater effects on vaccine confidence and intent to vaccinate compared to Centers for Disease Control and Prevention (CDC) and non-vaccine control messages.
Methods: A 3-arm randomized trial was conducted. Parents of girls aged 9-17 were eligible for the study. We measured participants' vaccine confidence and intent to vaccinate at baseline and post intervention message. Recruitment and surveys were administered online through Amazon Mechanical Turk.
Results: 762 participants completed both surveys. We saw modest increases in vaccine confidence when comparing cervical cancer arm and control arm, and CDC arm and control arm; estimates were not statistically significant. The odds of reporting intent to vaccinate among the cervical cancer message arm were 1.13 times the odds of reporting intent to vaccinate in the control arm (95% CI: 0.30. 4.29). Intent to vaccinate was also not statistically significantly different between CDC message arm and control arm (OR = 1.25, 95%CI: 0.66, 2.37).
Conclusion: Neither message had effect on intent to vaccinate, highlighting need for research to identify successful messaging strategies for HPV. Exploratory analyses suggest among parents with 'Low' vaccine confidence at baseline, the cervical cancer framed message may be more effective in changing intention than the CDC message or non-vaccine control. Future work should target groups with 'Low' or 'Medium' vaccine confidence at baseline - they may be more amenable to change, and more receptive to disease-salient messaging.
Clinical trial registration: Clinicaltrials.gov, Reference #: NCT03002324.
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