title: Quadrivalent vaccine against human papillomavirus to prevent high-grade cervical lesions.
abstract: BACKGROUND
  Human papillomavirus types 16 (HPV-16) and 18 (HPV-18) cause approximately 70% of cervical cancers worldwide. A phase 3 trial was conducted to evaluate a quadrivalent vaccine against HPV types 6, 11, 16, and 18 (HPV-6/11/16/18) for the prevention of high-grade cervical lesions associated with HPV-16 and HPV-18.
  
  
  METHODS
  In this randomized, double-blind trial, we assigned 12,167 women between the ages of 15 and 26 years to receive three doses of either HPV-6/11/16/18 vaccine or placebo, administered at day 1, month 2, and month 6. The primary analysis was performed for a per-protocol susceptible population that included 5305 women in the vaccine group and 5260 in the placebo group who had no virologic evidence of infection with HPV-16 or HPV-18 through 1 month after the third dose (month 7). The primary composite end point was cervical intraepithelial neoplasia grade 2 or 3, adenocarcinoma in situ, or cervical cancer related to HPV-16 or HPV-18.
  
  
  RESULTS
  Subjects were followed for an average of 3 years after receiving the first dose of vaccine or placebo. Vaccine efficacy for the prevention of the primary composite end point was 98% (95.89% confidence interval [CI], 86 to 100) in the per-protocol susceptible population and 44% (95% CI, 26 to 58) in an intention-to-treat population of all women who had undergone randomization (those with or without previous infection). The estimated vaccine efficacy against all high-grade cervical lesions, regardless of causal HPV type, in this intention-to-treat population was 17% (95% CI, 1 to 31).
  
  
  CONCLUSIONS
  In young women who had not been previously infected with HPV-16 or HPV-18, those in the vaccine group had a significantly lower occurrence of high-grade cervical intraepithelial neoplasia related to HPV-16 or HPV-18 than did those in the placebo group. (ClinicalTrials.gov number, NCT00092534 [ClinicalTrials.gov].).
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000517:prevention & control; D000293:Adolescent; D000328:Adult; D052685:Alphapapillomavirus; D004279:DNA, Viral / Q000097:blood; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D000068857:Human Papillomavirus Recombinant Vaccine Quadrivalent, Types 6, 11, 16, 18; D052162:Human papillomavirus 16 / Q000235:genetics / Q000302:isolation & purification; D052161:Human papillomavirus 18 / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D030361:Papillomavirus Infections / Q000517:prevention & control*; D053918:Papillomavirus Vaccines / Q000009:adverse effects; D013997:Time Factors; D016896:Treatment Outcome; D002583:Uterine Cervical Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D002578:Uterine Cervical Dysplasia / Q000453:epidemiology / Q000517:prevention & control*
chemical_list: D004279:DNA, Viral; D000068857:Human Papillomavirus Recombinant Vaccine Quadrivalent, Types 6, 11, 16, 18; D053918:Papillomavirus Vaccines