Missed opportunity: 12% of CHOP teens were not HPV-vaccinated before sexual activity

A research letter in JAMA Pediatrics analyzed electronic health records for 9,491 adolescents seen at Children's Hospital of Philadelphia clinics and found 79% completed the HPV vaccine series before sexual activity while 12% had received no doses.

A research letter in JAMA Pediatrics reports on HPV vaccination timing among adolescents seen in Children's Hospital of Philadelphia primary care clinics. The authors analyzed electronic health records for 9,491 patients aged 13 to 18 seen at 31 CHOP-affiliated practices from September 2023 to September 2025. All patients reported sexual activity on the clinic Adolescent Health Questionnaire. The study examined vaccination status before initiation of sexual activity and clinic-level practices linked with those outcomes. Key findings: - Overall, 79% of adolescents completed the HPV vaccine series before becoming sexually active, 12% had received no doses before sexual activity, and 9% had started but not completed the series. - Of those unvaccinated before sexual activity, 70% remained never vaccinated, 23% later initiated the series, and 7% completed the series after becoming sexually active. Unvaccinated patients were disproportionately White (49%) and commercially insured (59%). - Clinic-level pre-sex vaccination rates varied from 5% to 47%. Higher neighborhood opportunity, commercial insurance, and greater distance from the main hospital were associated with increased likelihood of not being vaccinated before sexual activity. - Clinics that more often began HPV vaccination at age nine had lower unvaccination rates, and the authors noted that family acceptance, clinician recommendation practices, and clinic workflows — rather than access to care — likely contribute to missed opportunities. Summary: The study highlights that a meaningful share of adolescents (12%) seen in primary care at CHOP had not received any HPV vaccine doses before reporting sexual activity, despite recent clinic visits. The authors report that starting vaccination earlier and routinizing practices—including presumptive communication, staff training, and workflow redesign—are associated with higher pre-sex vaccination rates, and they present these approaches as possible ways to reduce variation and missed opportunities.