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

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:

1. To estimate the CMI response in serologic non-responders after receiving a standard course of HBV immunization

   Secondary aims:

2. To establish the prevalence of serological non-responders after a standard course of HBV vaccination.

3. To assess the safety of the vaccine.

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

5. To compare the immunological profile before and after a standard HBV vaccination regimen on non-responders and responders

6. 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.

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).