University of Pennsylvania School of Engineering and Applied Science Jun 9 2026 A new Penn-led randomized controlled trial has found that AI-powered chatbots can make vaccine-hesitant parents more likely to say they will immunize their children against human papillomavirus (HPV), but no more than standard written public health materials. The findings raise questions about when, how and to what extent AI enhances public health communications. "Comparing a chatbot to nothing isn't really a fair