Trends in HPV vaccination among adults aged 27-45 years in the United States.

Despite expanded human papillomavirus (HPV) vaccination recommendations via shared clinical decision-making (SCDM) for adults aged 27-45 years (i.e., mid-adults), uptake remains low in the United States. Examining trends in HPV vaccination under SCDM across sociodemographic groups, vaccination sites, provider types, and geographical regions can offer insights into SCDM guideline implementation for HPV vaccination in eligible mid-adults. A retrospective cohort study was conducted using the Merative MarketScan® commercial claims database (2006-2023) to evaluate HPV vaccination uptake among mid-adults (aged 27-45 years). Annual and cumulative HPV vaccination rates (2019-2023) were analyzed overall and stratified by sociodemographic characteristics, provider type, and vaccination setting. Among the 3 to 4 million annually unvaccinated eligible adults aged 27-45 years identified in the database, the annual rate of HPV vaccination initiation rose modestly from 0.21% in 2019 to 0.54% in 2023 (5-year cumulative vaccination uptake: 0.84%). Most HPV vaccinations occurred in provider offices, though the proportion administered in pharmacies increased over time while the proportion in provider offices declined. Geographic variability in HPV vaccine uptake was substantial, with state-level rates ranging from 0.23% to 1.56%. These findings indicate that HPV vaccination uptake among mid-adults in the US remains low. Further research is needed to characterize geographic and sex-based variation in adult HPV vaccination and to further explore the growing role of pharmacies as HPV vaccination sites.