Angela W Chen, Edwin S Wong, Rachel L Winer, Monisha Sharma, Kristen E Gray
Objectives. To evaluate the association between school-entry vaccination mandates and adolescent human papillomavirus (HPV) vaccination uptake in the United States. Methods. We conducted a quasi-experimental study using a difference-in-differences approach comparing HPV vaccination uptake (≥ 1 dose) in mandate (n = 4) versus nonmandate (n = 47) states and territories by sex. We used provider-verified vaccination records from the 2008-2023 National Immunization Survey-Teen (n = 240 616) for adolescents aged 13 to 17 years. Models accounted for staggered policy implementation and adjusted for demographic and socioeconomic covariates. Results. School-entry mandates were associated with 6.4 percentage-points (95% confidence interval [CI] = 3.6, 9.1) higher HPV vaccination uptake among girls and 3.4 percentage points (95% CI = 1.8, 5.0) higher uptake among boys. Associations with HPV vaccination uptake increased over time for girls, whereas for boys, associations were concentrated in the first few years following implementation and attenuated thereafter. Conclusions. School-entry mandates are associated with higher HPV vaccination uptake among adolescents. Public Health Implications. Although mandates alone are unlikely to achieve national HPV vaccination targets, they may serve as an important component of comprehensive state efforts to increase uptake and prevent HPV-related cancers. (Am J Public Health. Published online ahead of print August 20, 2026:e1-e4. https://doi.org/10.2105/AJPH.2026.308635).