OBJECTIVES: We sought to identify effective responses to parents’ questions and concerns about human papillomavirus (HPV) vaccine. METHODS: In 2017–2018, we surveyed a national sample of 1196 US parents of children aged 9 to 17 years. We recorded brief videos of a pediatrician providing messages that addressed 7 HPV vaccination topics that commonly elicit questions or concerns (eg, recommended age). We randomly assigned parents to 1 of the message topics; parents then viewed 4 videos on that topic in random order and evaluated the messages. RESULTS: Parents were more confident in HPV vaccine when they were exposed to messages that addressed lack of knowledge about HPV vaccine (b = 0.13; P = .01), messages that included information about cancer prevention (b = 0.11; P < .001), messages that required a higher reading level (b = 0.02; P = .01), and messages that were longer (b = 0.03; P < .001). Parents were less confident in HPV vaccine when exposed to messages in which urgency was expressed (b = −0.06; P = .005). Analyses conducted by using HPV vaccine motivation as an outcome revealed the same pattern of findings. CONCLUSIONS: We provide research-tested messages that providers can use to address parents’ HPV vaccination questions and concerns about 7 common topics. Important principles for increasing message effectiveness are to include information on the benefits of vaccination (including cancer prevention) and avoid expressing urgency to vaccinate when addressing parents' questions or concerns. Additionally, providers may need to be prepared to have longer conversations with parents who express concerns about HPV vaccine, especially regarding safety and side effects
