The goal of this study is to learn if an innovative digital artificial intelligence (AI)-based communication tool works to enhance health literacy among Japanese caregivers regarding Human Papillomavirus (HPV) vaccination.

Participants will:

• Answer a pre-intervention survey, get information regarding HPV vaccination from an AI-based chatbot or leaflet, and answer a post-intervention survey.
• Continue interacting with the chatbot or leaflet for two weeks.
• Answer a follow-up survey.

This study will evaluate the efficacy and feasibility of an AI-driven chatbot in enhancing caregivers' health literacy about HPV vaccination and examines its impact on informed decision-making concerning their daughters' vaccination through a randomized controlled trial (RCT). To achieve this, the study will undertake the following interconnected activities:

1. Randomized Controlled Trial Participants will be randomly assigned to either the control or intervention group. Those in the control group will spend 5-10 minutes reading a publicly accessible HPV vaccination leaflet prepared by the MHLW, serving as the standard of care. Conversely, participants in the intervention group will be invited to interact with the chatbot for 5-10 minutes, posing inquiries (n>10) about HPV vaccination policies and related topics in Japan. Pre- and post-intervention assessments, as detailed below, will be administered to evaluate the chatbot's effectiveness and feasibility to counter HPV vaccine misinformation and support caregivers' vaccination decision-making processes.
2. Pre- and post-intervention assessments Following informed consent and enrollment, participants will complete a pre-intervention survey to establish baseline data. Post-intervention survey will be introduced at two touchpoints: the first is directly after spending time with either a leaflet (control) or a chatbot (intervention), and the second is two weeks after the first touchpoint.

The surveys are designed to assess the chatbot's effectiveness in enhancing caregivers' digital health literacy about HPV vaccination and facilitating informed vaccine decision-making.

Inclusion Criteria:

• A nationally representative sample of female caregivers with daughters aged 12-18 who have not received any HPV vaccine.
• Those who have access to a smartphone or computer with internet connectivity to interact with experiment materials (chatbot or online leaflet).
• Those who provide informed consent and agree to participate in the study.

Exclusion Criteria:

• Those who need help reading through the participant information sheet, providing consent online, accessing experiment materials (chatbot or online leaflet), or answering surveys will be excluded. This may include people who do not have access to an online environment or people with severe cognitive impairments who cannot interact with the experiment materials. Also, those who have participated or are participating in similar studies regarding vaccination or experiments that utilize chatbots will be excluded.