title: Human Papillomavirus Prevalence and Herd Immunity after Introduction of Vaccination Program, Scotland, 2009-2013.
abstract: In 2008, a national human papillomavirus (HPV) immunization program using a bivalent vaccine against HPV types 16 and 18 was implemented in Scotland along with a national surveillance program designed to determine the longitudinal effects of vaccination on HPV infection at the population level. Each year during 2009-2013, the surveillance program conducted HPV testing on a proportion of liquid-based cytology samples from women undergoing their first cervical screening test for precancerous cervical disease. By linking vaccination, cervical screening, and HPV testing data, over the study period we found a decline in HPV types 16 and 18, significant decreases in HPV types 31, 33, and 45 (suggesting cross-protection), and a nonsignificant increase in HPV 51. In addition, among nonvaccinated women, HPV types 16 and 18 infections were significantly lower in 2013 than in 2009. Our results preliminarily indicate herd immunity and sustained effectiveness of the bivalent vaccine on virologic outcomes at the population level.
authors.forename: Ross L
authors.initials: RL
authors.lastname: Cameron
authors.forename: Kimberley
authors.initials: K
authors.lastname: Kavanagh
authors.forename: Jiafeng
authors.initials: J
authors.lastname: Pan
authors.forename: John
authors.initials: J
authors.lastname: Love
authors.forename: Kate
authors.initials: K
authors.lastname: Cuschieri
authors.forename: Chris
authors.initials: C
authors.lastname: Robertson
authors.forename: Syed
authors.initials: S
authors.lastname: Ahmed
authors.forename: Timothy
authors.initials: T
authors.lastname: Palmer
authors.forename: Kevin G J
authors.initials: KG
authors.lastname: Pollock
mesh_terms: D000328:Adult; D056738:Cross Protection / Q000276:immunology; D005260:Female; D006801:Humans; D032521:Immunity, Herd / Q000276:immunology*; D017589:Immunization Programs / Q000379:methods; D027383:Papillomaviridae / Q000276:immunology*; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000276:immunology*; D053918:Papillomavirus Vaccines / Q000276:immunology*; D015995:Prevalence; D012606:Scotland / Q000453:epidemiology; D014611:Vaccination / Q000379:methods; D055815:Young Adult
chemical_list: D053918:Papillomavirus Vaccines
keywords: HPV; Scotland; cancer screening; cervical cancer; herd immunity; human papillomavirus vaccine; prevalence; vaccination; viruses