Digital Interventions to Increase HPV Vaccination Intentions Among Nigerian Caregivers

Cervical cancer remains a leading cause of cancer-related mortality among women in Nigeria. Persistent infection with high-risk types of human papillomavirus (HPV) is the primary cause of cervical cancer, and safe, effective vaccines are available and recommended for girls aged 9-14 years. Despite national and global efforts to expand access, HPV vaccination coverage in Nigeria remains low. Parental hesitancy, misinformation, limited knowledge, and lack of engagement with existing health communication materials are key barriers.

This randomized controlled trial examines whether different forms of digital communication can increase HPV vaccination intention among parents of unvaccinated, vaccine-eligible girls in Nigeria. The study focuses on scalable, low-cost interventions that could be deployed through mobile phones and other digital platforms.

Eligible participants are parents or primary caregivers of at least one unvaccinated girl aged 9-14 years. Participants will be individually randomized in equal proportions to one of five conditions:

A motivational interviewing-style chatbot that provides brief, interactive counseling adapted from World Health Organization vaccination guidance.

A short interactive "pre-bunking" game designed to build resistance to common forms of HPV vaccine misinformation.

A series of short edutainment videos providing information about HPV, cervical cancer prevention, and HPV vaccination in the Nigerian context.

A standard informational control consisting of existing HPV vaccination infographics produced by Nigeria's National Primary Health Care Development Agency.

An unrelated-content attention control consisting of infographics on menstruation awareness produced by a Nigerian health advocacy organization.

All content will be delivered digitally. Participants will complete baseline measures prior to randomization and follow-up surveys after exposure to the assigned content. The primary outcome is self-reported intention to vaccinate the selected daughter against HPV, measured immediately and one week post-intervention on a numeric scale. Secondary outcomes include HPV and vaccine-related knowledge, perceived vaccine safety, willingness to recommend the HPV vaccine to other parents, and self-reported HPV vaccine uptake. Additional intention measures will be collected 1-week after the intervention and at six months post-intervention, with vaccine uptake assessed at the six-month follow-up.

Primary analyses will be conducted under an intention-to-treat framework, comparing outcomes across randomized groups regardless of engagement with the assigned content. Secondary and exploratory analyses will examine engagement patterns and heterogeneity of effects by baseline attitudes, knowledge, and demographic characteristics.

The findings will provide evidence on the comparative effectiveness of different digital communication strategies for increasing HPV vaccination intention and uptake among parents in Nigeria and similar settings.

Inclusion criteria

• Parent or primary caregiver of at least one girl aged 9-14 years
• Parent states "no" or "unsure" to question asking if eligible daughter has received any doses of the HPV vaccine
• Provides informed consent to participate

Exclusion criteria

• Parent or caregiver of a girl who has already received one or more doses of the HPV vaccine
• Does not meet age eligibility criteria for an eligible daughter
• Fails Attention Checks