144 HPV vaccination coverage trends in Puerto Rico, 2017–2024: A retrospective repeated cross-sectional study using the PREIRS immunization registry

Objectives/Goals: To evaluate longitudinal trends in HPV vaccination initiation and series completion among adolescents aged 9–17 years in Puerto Rico from 2017 to 2024 and to determine the extent to which sustained coverage patterns following the 2018 school-entry mandate align with Healthy People 2030 targets. Methods/Study Population: A retrospective cross-sectional analysis was conducted using longitudinal registry data from PREIRS, Puerto Rico’s modernized immunization system integrating legacy PRIR records with electronic reporting. Records included adolescents with at least one vaccination event between 2017 and 2024 (N = 3,584,516). Vaccination status was categorized as initiated (≥ 1 HPV dose) or series completed (2–3 doses per ACIP recommendations) for each calendar year. Descriptive crosstabs and chi-square tests assessed annual differences (p < .001). Multiyear comparisons were performed independently for each cohort year to evaluate temporal changes, and stratified analyses were used to assess trends across sex and age groups. Data were analyzed using IBM SPSS Statistics (IBM Corp., Armonk, NY). Results/Anticipated Results: HPV vaccine initiation increased from 25.8% (2017) to 35.7% (2024), and series completion rose from 16.4% to 28.1% (χ²=18,498.85; df=7; p<.001). The steepest rise occurred between 2019–2021, coinciding with the school-entry mandate, followed by stabilization post-2021. Female coverage remained higher but differences narrowed annually. Publicly insured adolescents comprised over 80% of vaccine recipients, indicating socioeconomic influence. Coverage was highest among 11- to 13-year-olds, reflecting effective policy reach. Despite gains, both initiation and completion remain below the ≥80% Healthy People 2030 target, signaling the need for renewed HPV vaccination promotion and policy reinforcement among adolescents. Discussion/Significance of Impact: HPV vaccination gains in Puerto Rico demonstrate the sustained impact of the 2018 school-entry mandate and PREIRS infrastructure. Narrowing sex-based gaps indicate improved program consistency, while post-2021 plateau and public-insurance dominance highlight persistent socioeconomic barriers to long-term sustainability.