Disparities in Parental Knowledge and Intention to Vaccinate Against HPV by Children’s Sex: Implications for Equitable Prevention Policy

Human papillomavirus (HPV) infection is a leading cause of cancers and genital warts in men and women. Although HPV vaccination programs for all genders are widely implemented internationally, limited research has examined parental intention to vaccinate after the Japanese government’s reinstatement of active vaccination recommendations for girls and introduction of voluntary vaccination for boys. A cross-sectional survey was conducted between November and December 2024, among parents of 511 junior high school students at a single school, yielding 200 valid responses. Chi-square tests and binary logistic regression analysis were employed to identify factors associated with vaccination intention (previously vaccinated or intention to vaccinate versus negative intention or undecided). Significant predictors of vaccination intention included sibling composition (only sons); information from pediatricians; prior vaccination of daughters’ or acquaintances’ children; recognition of vaccine effectiveness; the belief that screening alone is sufficient; and recognition of follow-up systems for adverse events. Parental vaccination intention was influenced by trusted medical information, social networks, recognition of vaccine effectiveness/safety, HPV-related knowledge, and child’s sex. These findings highlight the importance of gender-neutral information and preventive measures to ensure equitable support for all parents regardless of child’s sex.