title: Characteristics of immune memory 10-15 years after primary hepatitis B vaccination.
abstract: OBJECTIVE
  The definition of immune memory after hepatitis B vaccination is still under debate. Therefore, we analysed hepatitis B surface antigen (HBsAg)-specific memory in more detail by investigating the kinetics of humoral and cellular responses after hepatitis B booster vaccination.
  
  
  METHODS
  The anti-HBs kinetics of 23 individuals with anti-HBs titres below 10 IU/l, who had been vaccinated 10-15 years ago, was monitored at day 0, 3, 7, 14 and 28 after booster vaccination. HBsAg-specific IFNγ- and IL5-secreting cells in enriched CD4(+) fraction were measured at day 0, 7 and 28 post-booster by enzyme-linked immunospot assay (ELISpot).
  
  
  RESULTS
  22 of 23 subjects showed similar anti-HBs kinetic curves, including 3 of 4 subjects who did not reach anti-HBs titres of 10 IU/l. The steep anti-HBs increase started between day 3 and 7 and peaked around day 14. A plateau or only minimal changes were visible between day 14 and 28. 17.4% of subjects showed pre-booster cellular responses, and this rate had increased to 47.8% and 56.5% after 7 and 28 days, respectively. The kinetic patterns of T cell responses differed considerably among subjects. A dominance of Th2 responses (IL5 secretion) over Th1 responses (IFNγ secretion) could be observed.
  
  
  CONCLUSIONS
  The presence of B cell memory could be shown by a typical anamnestic anti-HBs response curve after a booster dose in all but one individual. In contrast, T cell responses to booster vaccination, which occurred in approximately 50% of participants, were rather heterogeneous.
authors.affiliation: Institute of Medical Microbiology and Hygiene, University of Regensburg, 93053 Regensburg, Germany. Electronic address: irena.hummel@klinik.uni-regensburg.de.
authors.forename: Irena
authors.initials: I
authors.lastname: Brunskole Hummel
authors.affiliation: Institute of Medical Microbiology and Hygiene, University of Regensburg, 93053 Regensburg, Germany. Electronic address: anita-zitzmann@t-online.de.
authors.forename: Anita
authors.initials: A
authors.lastname: Zitzmann
authors.affiliation: Institute of Medical Microbiology and Hygiene, University of Regensburg, 93053 Regensburg, Germany. Electronic address: monika.erl@klinik.uni-regensburg.de.
authors.forename: Monika
authors.initials: M
authors.lastname: Erl
authors.affiliation: Institute of Clinical Microbiology and Hygiene, University Medical Centre Regensburg, 93053 Regensburg, Germany. Electronic address: juergen.wenzel@klinik.uni-regensburg.de.
authors.forename: Jürgen J
authors.initials: JJ
authors.lastname: Wenzel
authors.affiliation: Institute of Medical Microbiology and Hygiene, University of Regensburg, 93053 Regensburg, Germany. Electronic address: wolfgang.jilg@klinik.uni-regensburg.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Jilg
mesh_terms: D000293:Adolescent; D001402:B-Lymphocytes / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D006509:Hepatitis B / Q000517:prevention & control; D006510:Hepatitis B Antibodies / Q000097:blood*; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000627:therapeutic use*; D006801:Humans; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D007117:Immunization, Secondary; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000276:immunology; D015848:Interleukin-5 / Q000276:immunology; D008297:Male
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; C573415:IFNG protein, human; C508599:IL5 protein, human; D015848:Interleukin-5; D007371:Interferon-gamma
keywords: Anti-HBs titre; Cellular immunity; ELISpot; Hepatitis B vaccination; Immune memory; Kinetics