title: Long-term clinical impact of introducing a human papillomavirus 16/18 AS04 adjuvant cervical cancer vaccine in Spain.
abstract: BACKGROUND
  Human papillomavirus (HPV) epidemiology and screening practices vary considerably between countries and specific analyses are required to estimate the impact of HPV vaccination. This study aimed to predict the clinical benefits of introducing a bivalent HPV16/18 vaccine in Spain, where the cervical cancer (CC) incidence is 10.3 per 100 000.
  
  
  METHODS
  A Markov model based upon the natural history of HPV and CC was developed to simulate transitions between health states, in the presence of specific screening programmes. Published data were used to reflect the Spanish situation in terms of epidemiological characteristics, screening and treatment practices. Calibration consisted of varying disease progression rates within established ranges until model predictions matched observed epidemiological data. The clinical impact of vaccinating a cohort of 12-year-old girls against HPV was assessed over their lifetime using the calibrated model.
  
  
  RESULTS
  Vaccination of all 12-year-old girls would result in a reduction of 75% (from 0.32% to 0.08%) in the prevalence of high-grade precancerous lesions due to oncogenic HPV, and a 79% reduction in both CC cases (from 1745 to 365) and CC deaths (from 417 to 86). Assuming a vaccine coverage of 80%, the number of CC cases and deaths would decrease by 63%. Vaccination could also substantially reduce the number of screening tests and treatments required for cervical dysplasia.
  
  
  CONCLUSIONS
  Our model was successfully adapted to the Spanish epidemiological environment, screening and treatment practices and predicted a substantial long-term benefit of HPV vaccination despite a low HPV prevalence in Spain.
authors.affiliation: i3 Innovus, Uxbridge, UK. aline.gauthier@i3innovus.com
authors.forename: Aline
authors.initials: A
authors.lastname: Gauthier
authors.forename: Victoria
authors.initials: V
authors.lastname: Martín-Escudero
authors.forename: Lee
authors.initials: L
authors.lastname: Moore
authors.forename: Nicole
authors.initials: N
authors.lastname: Ferko
authors.forename: Silvia
authors.initials: S
authors.lastname: de Sanjosé
authors.forename: Isabel
authors.initials: I
authors.lastname: Pérez-Escolano
authors.forename: Ferrán
authors.initials: F
authors.lastname: Catalá-López
authors.forename: Elena
authors.initials: E
authors.lastname: Ferrer
authors.forename: F Xavier
authors.initials: FX
authors.lastname: Bosch
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D052162:Human papillomavirus 16 / Q000276:immunology; D052161:Human papillomavirus 18 / Q000276:immunology; D006801:Humans; D015994:Incidence; D008390:Markov Chains; D008403:Mass Screening; D008875:Middle Aged; D015233:Models, Statistical; D030361:Papillomavirus Infections / Q000517:prevention & control*; D053918:Papillomavirus Vaccines / Q000627:therapeutic use*; D015995:Prevalence; D012680:Sensitivity and Specificity; D013030:Spain; D002583:Uterine Cervical Neoplasms / Q000517:prevention & control*
chemical_list: D053918:Papillomavirus Vaccines; C510352:human papillomavirus vaccine, L1 type 16, 18