HPV vaccine uptake rises with help from AI chatbot

The first trial of an AI (Artificial Intelligence)-powered chatbot designed to inform parents about the HPV vaccine has shown that it increases vaccine uptake and engagement with health professionals.

Cervical cancer, caused by human papillomavirus (HPV), is one of the most preventable cancers, yet it still claims over 340,000 lives annually. China accounts for 22.8% of global cases, with vaccine coverage remaining low.

The 24/7 chatbot was designed to deliver trusted, personalised vaccine information to parents in a user-friendly way, through simulating human conversations and responding to parent's frequently asked questions about HPV, the safety of the vaccine, eligibility, side effects, costs and where they could access services.

The school-based randomised controlled trial followed a total of 2,671 parents of girls aged 12 to 15 for two weeks, after being randomly assigned to receive either usual care (standard health promotion of the HPV vaccine) or the chatbot intervention. The parents of children across 180 classes were enrolled, spanning megacity, urban and rural settings in Shanghai and Anhui Province, China.

The study was conducted under the Moonrise Initiative, a pioneering effort leveraging artificial intelligence to advance women's health and health equity. The initiative is co-led by the InnoHK Laboratory of Data Discovery for Health (D²4H) and the School of Public Health at the University of Hong Kong, alongside the Vaccine Confidence Project™ at the London School of Hygiene & Tropical Medicine, in partnership with Fudan University in Shanghai, China. This international consortium brings together leading experts in digital health, behavioral science, and epidemiology to tackle urgent global challenges at the intersection of technology, trust, and women's well-being.

The findings, published in Nature Medicine, suggest that interaction with the AI tool may influence vaccination behaviour. Girls were three-times more likely to have their HPV vaccination scheduled or received if their parents interacted with the chatbot compared with those who only received routine health promotion (7.1% and 1.8% respectively). Around 49.1% of parents in the chatbot group also consulted with a health professional about the vaccine, compared with 17.6% of parents in the control group.

The impact was especially pronounced in rural areas, where parents in the chatbot group were 8.81 times more likely to initiate vaccination than those receiving standard information.

Dr. Leesa Lin, senior author and Associate Professor at LSHTM and D²4H, said: "This is one of several real-world chatbot trials we're leading globally. What's unique here is the focus on equity—this intervention was designed not just for scale, but to reach those too often overlooked, particularly in women's health."

Delivering a scalable, trusted solution to public questions about vaccines is what global health innovation should strive for. This study offers a replicable approach to addressing questions and concerns raised by the public - challenges faced worldwide."

Professor Heidi Larson, Founding Director of the Vaccine Confidence Project at LSHTM

Professor Joseph Wu, Managing Director of D²4H and Sir Robert Kotewall Professor in Public Health at HKU, said: "This study shows how scientific rigor and digital innovation can drive immediate, measurable change—especially in moments of public health urgency. This initiative highlights the power of AI not only to personalise care but also to reduce global health disparities. In under-resourced settings, tools like this can be transformative."

In China, structural barriers, particularly high out-of-pocket costs and limited supply of the recommended HPV vaccine, play a major role in limiting uptake, even among parents who are willing to vaccinate. The team emphasise that while hesitancy exists, issues like affordability, long wait times and uneven access often have a greater influence on behaviour, especially in rural and lower-income settings.

The research team is now working to scale up the chatbot in other countries, including Japan, where HPV vaccine hesitancy has long been a concern. While the initial intervention focused on adolescent girls, the team say it can also be adapted for parents of boys, aligning with global trends toward gender-inclusive HPV vaccination.

The chatbot model is also being adapted for broader health challenges, including mental health, maternal and child health, and pandemic preparedness.