Investigators from the Centers for Disease Control and Prevention (CDC) determined the prevalence of HPV infection among females aged 14 to 59 years during the pre-HPV vaccine era (2003–2006) and postvaccine era (2007–2010). These eras were delineated by the June 2006 recommendation for HPV vaccination, which was published in early 2007.¹ Data were collected as part of the National Health and Nutrition Examination Survey (NHANES), an ongoing national survey conducted by the CDC that includes a household interview and a physical examination. Demographic data, sexual history, and a self-collected cervicovaginal swab were obtained from all participants, and HPV vaccination history was obtained via self-report. Cervicovaginal swabs were analyzed for 37 HPV types, classified as vaccine types, high-risk (HR) vaccine types, and HR nonvaccine types (12 clinically relevant types). Investigators used logistic regression to determine prevalence ratios (PR) for the total participant population as well as for 6 age groups between 14 and 59 years. Adjusted prevalence ratios (aPR) among a subgroup of sexually active females aged 14 to 19 years were also calculated. Vaccine effectiveness among 14- to 19-year-old females who reported sexual activity was estimated.

There were 4,150 prevaccine era and 4,253 postvaccine era participants included in the analysis. In the postvaccine cohort, 34% reported receipt of ≥1 vaccine doses and 63% reported receipt of all 3 doses. There was no significant difference in HPV prevalence in the postvaccine era compared to the prevaccine era in all age groups except among those aged 14 to 19 years. In the 14 to 19 age group, the prevalence of any HPV type (PR 0.79; 95% CI, 0.66–0.95), vaccine types (PR 0.44; 95% CI, 0.31–0.62), and HR vaccine types (PR 0.50; 95% CI, 0.34–0.74) were all significantly lower in the postvaccine era. There were no differences in sexual activity, number of lifetime sex partners, or race/ethnicity between 14- to 19-year-old participants in the prevaccine and postvaccine cohorts.

Among the subset of sexually active 14- to 19-year-old participants, the prevalence of any HPV type (aPR 0.82; 95% CI, 0.69–0.98) and vaccine types (aPR 0.47; 95% CI, 0.33–0.67) was lower in the postvaccine cohort compared to the prevaccine cohort. Among those in this subset who received at least 1 vaccine dose, the adjusted prevalence of vaccine types was even lower (aPR 0.18; 95% CI, 0.07–0.47), resulting in an estimated vaccine effectiveness of 82%.

The authors conclude that after HPV vaccine recommendations, vaccine HPV types have decreased 56% among 14- to 19-year-old females despite low HPV vaccine uptake.