title: Prevalence of HPV After Introduction of the Vaccination Program in the United States.
abstract: BACKGROUND
  Since mid-2006, human papillomavirus (HPV) vaccination has been recommended for females aged 11 to 12 years and through 26 years if not previously vaccinated.
  
  
  METHODS
  HPV DNA prevalence was analyzed in cervicovaginal specimens from females aged 14 to 34 years in NHANES in the prevaccine era (2003-2006) and 4 years of the vaccine era (2009-2012) according to age group. Prevalence of quadrivalent HPV vaccine (4vHPV) types (HPV-6, -11, -16, and -18) and other HPV type categories were compared between eras. Prevalence among sexually active females aged 14 to 24 years was also analyzed according to vaccination history.
  
  
  RESULTS
  Between the prevacccine and vaccine eras, 4vHPV type prevalence declined from 11.5% to 4.3% (adjusted prevalence ratio [aPR]: 0.36 [95% confidence interval (CI): 0.21-0.61]) among females aged 14 to 19 years and from 18.5% to 12.1% (aPR: 0.66 [95% CI: 0.47-0.93]) among females aged 20 to 24 years. There was no decrease in 4vHPV type prevalence in older age groups. Within the vaccine era, among sexually active females aged 14 to 24 years, 4vHPV type prevalence was lower in vaccinated (≥1 dose) compared with unvaccinated females: 2.1% vs 16.9% (aPR: 0.11 [95% CI: 0.05-0.24]). There were no statistically significant changes in other HPV type categories that indicate cross-protection.
  
  
  CONCLUSIONS
  Within 6 years of vaccine introduction, there was a 64% decrease in 4vHPV type prevalence among females aged 14 to 19 years and a 34% decrease among those aged 20 to 24 years. This finding extends previous observations of population impact in the United States and demonstrates the first national evidence of impact among females in their 20s.
authors.affiliation: Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, and lem2@cdc.gov.
authors.forename: Lauri E
authors.initials: LE
authors.lastname: Markowitz
authors.affiliation: Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, and.
authors.forename: Gui
authors.initials: G
authors.lastname: Liu
authors.affiliation: Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, and.
authors.forename: Susan
authors.initials: S
authors.lastname: Hariri
authors.affiliation: Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Martin
authors.initials: M
authors.lastname: Steinau
authors.affiliation: Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, and.
authors.forename: Eileen F
authors.initials: EF
authors.lastname: Dunne
authors.affiliation: Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Unger
mesh_terms: D000293:Adolescent; D000328:Adult; D052685:Alphapapillomavirus / Q000235:genetics; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D006801:Humans; D017589:Immunization Programs; D009749:Nutrition Surveys; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000517:prevention & control*; D053918:Papillomavirus Vaccines / Q000008:administration & dosage*; D015995:Prevalence; D012725:Sexual Behavior; D014481:United States / Q000453:epidemiology; D014611:Vaccination; D014626:Vaginal Smears; D055815:Young Adult
chemical_list: D004279:DNA, Viral; D053918:Papillomavirus Vaccines