title: Enhanced immunogenicity of recombinant hepatitis B vaccine in exposed family contacts of chronic liver disease patients.
abstract: Close family contacts of hepatitis B virus (HBV)-related chronic liver disease patients have a high risk of exposure to HBV. Variable responses to vaccination have been reported in family contacts, especially in previously exposed contacts (IgG antiHBc-positive). Seventy-nine healthy family contacts, who were HBsAg-negative with normal alanine amino-transferase level and no evidence of liver disease, were vaccinated using a recombinant HBV vaccine, irrespective of past exposure status. A significantly higher number of previously exposed subjects (n = 25; Group I) developed early seroprotective anti-HBs titers with 2 initial doses of vaccine compared to the unexposed contacts (Group II; n = 54) (64% vs. 33%, respectively; P < 0.05). However, the responses were comparable on completion of the schedule (96% vs. 94%, respectively). HBV DNA was detected in 11 of 25 (44%) exposed and none of the unexposed contacts at baseline. Post-vaccination, 3 of 11 (27%) subjects became HBV DNA-negative and remained negative for the next 12 months. These results suggest that exposed family contacts achieve efficient seroprotection after HBV vaccination, irrespective of the IgG anti-HBc status. The response to vaccination resembles an anamnestic reaction and possibly demonstrates a therapeutic effect.
authors.affiliation: Department of Gastroenterology, G. B. Pant Hospital, New Delhi, India.
authors.forename: V
authors.initials: V
authors.lastname: Thakur
authors.forename: R C
authors.initials: RC
authors.lastname: Guptan
authors.forename: S F
authors.initials: SF
authors.lastname: Basir
authors.forename: M K
authors.initials: MK
authors.lastname: Parvez
authors.forename: S K
authors.initials: SK
authors.lastname: Sarin
mesh_terms: D000293:Adolescent; D000328:Adult; D004279:DNA, Viral / Q000302:isolation & purification; D004781:Environmental Exposure; D005260:Female; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006515:Hepatitis B virus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D019694:Hepatitis B, Chronic / Q000276:immunology* / Q000517:prevention & control*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D014614:Vaccines, Synthetic