title: Are the Two Human Papillomavirus Vaccines Really Similar? A Systematic Review of Available Evidence: Efficacy of the Two Vaccines against HPV.
abstract: BACKGROUND
  When the bivalent and the quadrivalent HPV vaccines were marketed they were presented as having comparable efficacy against cervical cancer. Differences between the vaccines are HPV types included and formulation of the adjuvant.
  
  
  METHODS
  A systematic review was conducted to assess the efficacy of the two vaccines against cervical cancer. Outcomes considered were CIN2+, CIN3+, and AIS.
  
  
  RESULTS
  Nine reports (38,419 women) were included. At enrollment mean age of women was 20 years, 90% had negative cytology, and 80% were seronegative and/or DNA negative for HPV 16 or 18 (naïve women). In the TVC-naïve, VE against CIN2+ was 58% (95% CI: 35, 72); heterogeneity was detected, VE being 65% (95% CI: 54, 74) for the bivalent and 43% (95% CI: 23, 57) for the quadrivalent. VE against CIN3+ was 78% (95% CI: <0, 97); heterogeneity was substantial, VE being 93% (95% CI: 77, 98) for the bivalent and 43% (95% CI: 12, 63) for the quadrivalent. VE in the TVC was much lower. No sufficient data were available on AIS.
  
  
  CONCLUSIONS
  In naïve girls bivalent vaccine shows higher efficacy, even if the number of events detected is low. In women already infected the benefit of the vaccination seems negligible.
authors.affiliation: SaPeRiDoc Unit, Department of Primary Health Care, Regional Health Authority of Emilia-Romagna, Viale Aldo Moro 21, 40127 Bologna, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Di Mario
authors.affiliation: SaPeRiDoc Unit, Department of Primary Health Care, Regional Health Authority of Emilia-Romagna, Viale Aldo Moro 21, 40127 Bologna, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Basevi
authors.affiliation: Office of Chief Scientist, European Centre for Disease Prevention and Control (ECDC), 171 83 Stockholm, Sweden.
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Lopalco
authors.affiliation: Statistics Unit, Department of Diagnostic and Clinical Medicine and Public Health, University of Modena & Reggio Emilia, Via del Pozzo 71, 41100 Modena, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Balduzzi
authors.affiliation: Statistics Unit, Department of Diagnostic and Clinical Medicine and Public Health, University of Modena & Reggio Emilia, Via del Pozzo 71, 41100 Modena, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: D'Amico
authors.affiliation: Drug Evaluation Unit, WHO Collaborating Centre for Evidence Based Research Synthesis and Guidelines Development, Regional Health and Social Agency of Emilia-Romagna, Viale Aldo Moro 21, 40127 Bologna, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Magrini
mesh_terms: D000328:Adult; D052685:Alphapapillomavirus / Q000145:classification / Q000276:immunology*; D002986:Clinical Trials as Topic; D005260:Female; D014943:Global Health; D006801:Humans; D009367:Neoplasm Staging; D017063:Outcome Assessment, Health Care; D030361:Papillomavirus Infections / Q000150:complications / Q000517:prevention & control* / Q000821:virology; D053918:Papillomavirus Vaccines / Q000145:classification / Q000276:immunology*; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*
chemical_list: D053918:Papillomavirus Vaccines