title: Hepatitis A and B immunity and vaccination in chronic hepatitis B and C patients in a large United States cohort.
abstract: BACKGROUND
  Hepatitis A and B vaccines are effective in preventing superinfection and sequelae in patients with chronic hepatitis B or C. We describe immunity and vaccination against hepatitis A and B in chronic hepatitis patients from the US Chronic Hepatitis Cohort Study.
  
  
  METHODS
  We identified chronic hepatitis B and C patients with healthcare utilization during 2006-2008 and 12 months of enrollment. We used electronic laboratory records to determine immunity and medical and billing records for vaccination history. Immunity against hepatitis A was defined by positive hepatitis A antibody or documented vaccination. Immunity against hepatitis B was defined as hepatitis B surface antibody level ≥10 mIU/mL or core antibody positive, or by documented vaccination.
  
  
  RESULTS
  Among 1635 chronic hepatitis B patients, 978 (59.8%) were immune or vaccinated against hepatitis A, 122 (7.5%) had negative hepatitis A antibody tests, and 535 (32.7%) had no testing or vaccination record. Among 5328 chronic hepatitis C patients, 2998 (56.3%) were immune or vaccinated against hepatitis A, 659 (12.4%) had negative hepatitis A antibody tests, and 1671 (31.4%) had no testing or vaccination record. Additionally, 3150 (59.1%) chronic hepatitis C patients were immune or vaccinated against hepatitis B, 1003 (18.8%) had a negative test result, and 1175 (22.1%) were neither tested for nor vaccinated against hepatitis B.
  
  
  CONCLUSIONS
  Approximately 40% of chronic hepatitis B and C patients are susceptible to or have no documented immunity or vaccination against hepatitis A or hepatitis B. Clinicians should consider antibody testing and vaccination for this vulnerable population.
authors.affiliation: Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon.
authors.forename: Emily
authors.initials: E
authors.lastname: Henkle
authors.affiliation: Henry Ford Health System, Detroit, Michigan.
authors.forename: Mei
authors.initials: M
authors.lastname: Lu
authors.affiliation: Henry Ford Health System, Detroit, Michigan.
authors.forename: Lora B
authors.initials: LB
authors.lastname: Rupp
authors.affiliation: Geisinger Health System, Danville, Pennsylvania.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Boscarino
authors.affiliation: Center for Health Research, Kaiser Permanente, Honolulu, Hawaii.
authors.forename: Vinutha
authors.initials: V
authors.lastname: Vijayadeva
authors.affiliation: Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Schmidt
authors.affiliation: Henry Ford Health System, Detroit, Michigan.
authors.forename: Stuart C
authors.initials: SC
authors.lastname: Gordon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D006506:Hepatitis A / Q000276:immunology* / Q000517:prevention & control; D035922:Hepatitis A Antibodies / Q000097:blood; D022362:Hepatitis A Vaccines / Q000276:immunology; D006509:Hepatitis B / Q000276:immunology* / Q000517:prevention & control; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000276:immunology; D019694:Hepatitis B, Chronic / Q000276:immunology*; D019698:Hepatitis C, Chronic / Q000276:immunology*; D006801:Humans; D008499:Medical Records; D008875:Middle Aged; D015999:Multivariate Analysis; D014481:United States; D014611:Vaccination; D055815:Young Adult
chemical_list: D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines
keywords: chronic hepatitis; hepatitis A; hepatitis B; hepatitis C; vaccination