title: Effectiveness of the targeted hepatitis B vaccination program in Greenland.
abstract: OBJECTIVE
  To evaluate the effectiveness of the hepatitis B virus (HBV) vaccination program in Greenland, which targets children born to mothers who are positive for HBV surface antigen (HBsAg), we determined vaccination coverage, levels of postvaccination antibodies, and frequency of breakthrough infections in at-risk children.
  
  
  METHODS
  We conducted a population-based retrospective cohort study with data from nationwide registries. We identified all children born to HBsAg-positive mothers from 1992 to 2007 and collected data on their HBV vaccination status. In 2008 to 2010, we tested the children for HBV core antibody, HBsAg, and anti-HBsAg antibody (HBsAb).
  
  
  RESULTS
  Of 4050 pregnant women, 3.2% were HBsAg positive. Of 207 children born to these women, 20% received no vaccinations, and only 58% received at least 3 vaccinations. At follow-up, HBsAb levels in vaccinated children were much lower than expected, and 8 (6%) of 140 at-risk children had breakthrough infections, with 4 chronically infected (persistently HBsAg positive).
  
  
  CONCLUSIONS
  The prevention program targeting children at risk for HBV in Greenland is ineffective. HBV vaccination should be included in the universal childhood vaccination program, and postvaccination HBsAb levels should be monitored.
authors.affiliation: Department of Epidemiology Research, Statens Serum Institut (SSI), Copenhagen, Denmark. mlb@ssi.dk
authors.forename: Malene L
authors.initials: ML
authors.lastname: Børresen
authors.forename: Anders
authors.initials: A
authors.lastname: Koch
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Biggar
authors.forename: Karin
authors.initials: K
authors.lastname: Ladefoged
authors.forename: Mads
authors.initials: M
authors.lastname: Melbye
authors.forename: Jan
authors.initials: J
authors.lastname: Wohlfahrt
authors.forename: Tyra Grove
authors.initials: TG
authors.lastname: Krause
mesh_terms: D000328:Adult; D005260:Female; D006116:Greenland / Q000453:epidemiology; D006509:Hepatitis B / Q000517:prevention & control* / Q000635:transmission; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood; D017325:Hepatitis B Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D006801:Humans; D017589:Immunization Programs / Q000706:statistics & numerical data*; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D009035:Mothers; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology*; D015397:Program Evaluation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines