title: Modelling patterns of clearance of HPV-16 infection and vaccination efficacy.
abstract: A model representing carcinogenic HPV infection transmission dynamics and cervical cancer natural history was adapted to assess the consequences of introducing vaccination against HPV-16 infection. Alternative scenarios either allowing repeated infections with the HPV-16 (i.e. SIS scenario) or assuming that clearance of infection occurs through the development of a long lasting, specific immune response which protects against re-infection (i.e. SIR scenario) were investigated. The difference in reduction in lifetime cervical cancer achieved through vaccination of 12-year-old girls, between SIS and SIR scenarios, was up to 25% of expected cases in an unscreened population. This difference increased to 30% when vaccination of 12-year-old boys was also included as an intervention. The role of SIS or SIR dynamics should be accounted for in the assessment of model-based projections of the effectiveness of vaccination programmes, until available data about the transmission dynamics support the accuracy of model predictions.
authors.affiliation: SCDU di Epidemiologia dei Tumori, Servizio di Statistica Medica, CPO Piemonte, Novara, Italy. i.baussano06@imperial.ac.uk
authors.forename: Iacopo
authors.initials: I
authors.lastname: Baussano
authors.forename: Geoff
authors.initials: G
authors.lastname: Garnett
authors.forename: Nereo
authors.initials: N
authors.lastname: Segnan
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Ronco
authors.forename: Paolo
authors.initials: P
authors.lastname: Vineis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D052162:Human papillomavirus 16 / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D030361:Papillomavirus Infections / Q000150:complications / Q000517:prevention & control* / Q000821:virology; D053918:Papillomavirus Vaccines / Q000276:immunology*; D002583:Uterine Cervical Neoplasms / Q000517:prevention & control* / Q000821:virology; D014594:Uterine Neoplasms / Q000517:prevention & control* / Q000821:virology; D055815:Young Adult
chemical_list: D053918:Papillomavirus Vaccines