Cellular Immunity in Adult Hepatitis B-vaccinated Serologic Non-responders

Previous studies have shown that 5-10% of Hepatitis B Virus vaccine recipients produce none or to few antibodies after a standard immunization with 3 vaccines. These individuals are defined as non-responders. The investigators wish to investigate if mounting another kind of immune response, called the cellular immune (CMI) response, protects these non-responders. Aim/Hypothesis Primary aims: To estimate the CMI response in serologic non-responders after receiving a standard course of HBV immunization Secondary aims: To establish the prevalence of serological non-responders after a standard course of HBV vaccination. To assess the safety of the vaccine. Evaluate predictors of serologic non-response in young, healthy individuals receiving a standard course of HBV immunization To compare the immunological profile before and after a standard HBV vaccination regimen on non-responders and responders Establish a rapid test for measuring CMI after being HBV vaccinated. A total of 400 healthy volunteers receive a standard course of immunization with a combined hepatitis A and B vaccine (Twinrix®) at 0, 1, and 6 months. Blood is drawn at 0 and 8 months from all participants. The blood will be analysed to see if there is antibodies or/and if there is mounted a cellular immune response by measuring on parameters called cytokines.

A total of 400 healthy volunteers receive a standard course of immunization with a combined hepatitis A and B vaccine (Twinrix®) at 0, 1, and 6 months. Twinrix ® Adult suspension for injection. 1 ml contains 720 ELISA units of hepatitis A virus antigen adsorbed to aluminum hydroxide and 20 micrograms hepatitis B surface antigen (HBsAg) adsorbed to aluminum phosphate in sterile water. Excipient: sodium chloride. Contains traces of neomycin.

Estimate the CMI response in serologic non-responders after receiving a standard course of HBV immunization

Preparation of peripheral blood mononuclear cells (PBMC) Optimisation of antigen-specific cytokine flow cytometry Quantification of IFN-γ producing CD4+ T cells

Establish the prevalence of serological non-responders after a standard course of HBV vaccination defined by anti-HBs <10 mIU / ml

Antibodies to Hepatitis B surface antigen are detected by use of a comercially available kit at the department of Clinical Immunology, Aarhus University Hospital, Skejby

Assess the safety of the vaccine by evaluating the numbers and intensity of adverse and Serious adverse events

Evaluate predictors of serologic non-response in young, healthy individuals receiving a standard course of HBV immunization

Questionnaire and *Magnitude of HBsAg-specific cell-mediated immune response.The presence of antigen specifik single, double or triple cytokine-producing T cells. Numbers and fractions of antigen-specific CD4 and CD8 T cells *HBsAg-specific T cell proliferation is quantified*The difference in phenotypic T cell profiles is getting compared at baseline*HBsAg-specific B cells measured by flow cytometry with staining for surface markers*Supernatant from HBsAg-stimulated PBMC is analysed regarding cytokines* Production of pro- og antiinflammatory cytokines is assesed by RT-PCR .

Compare the immunological profile before and after a standard HBV vaccination regimen, with com-parison of serological non-responders and serological responders

Magnitude of HBsAg-specific cell-mediated immune response.The presence of antigen specifik single, double or triple cytokine-producing T cells. Numbers and fractions of antigen-specific CD4 and CD8 T cells *HBsAg-specific T cell proliferation is quantified*The difference in phenotypic T cell profiles is getting compared at baseline*HBsAg-specific B cells measured by flow cytometry with staining for surface markers*Supernatant from HBsAg-stimulated PBMC is analysed regarding cytokines* Production of pro- og antiinflammatory cytokines is assesed by RT-PCR .

Preparation of peripheral blood mononuclear cells (PBMC) Optimisation of antigen-specific cytokine flow cytometry Quantification of IFN-γ producing CD4+ T cells

Inclusion Criteria: Signed participant information and consent Age over 18 years Women of childbearing potential must use effective contraceptives Exclusion Criteria: previous HBV infection previous HBV immunization pregnancy (or planned pregnancy within 6 months) allergy to contents in the vaccine (formaldehyde).