Duration of Long-term Immunity After Hepatitis B Virus Immunization

Hepatitis B vaccine is very effective at preventing infection with the hepatitis B virus (HBV). Several studies have reported on the long-term efficacy of the HBV vaccine and indicate a decline in titers of antibody against hepatitis B surface antigen (anti-HBs) over time. However, most of these studies were performed in persons vaccinated as infants or children. This protocol is designed to examine the long-term immune status of HIV positive and negative individuals who were vaccinated during adulthood, and to compare it to the immune status of individuals who acquired natural immunity by recovering from acute hepatitis B during adulthood. Individuals who lost the vaccine-induced humoral immune response, will be offered a booster vaccination and their immune response to the booster vaccination will be assessed. In this study, we will recruit 150 subjects who were vaccinated secondary to their job-related risk of acquiring HBV infection. An additional 50 subjects who had spontaneously recovered from acute hepatitis B (Bullet) 10 years ago, 50 patients with well-compensated HIV infection who received HBV vaccine (Bullet) 10 years ago and 10 subjects who were never vaccinated and never infected with the hepatitis B virus will be enrolled as comparison groups. All subjects will be asked to complete a questionnaire to assess their HBV exposure risk as well as factors that may affect their immune response. Immunological assays include the quantitation of HBV-specific antibodies and the qualitative and quantitative assessment of HBV-specific memory B cells and T cells at the indicated time intervals after vaccination or after recovery from acute hepatitis B. Additional immunological assays include testing for antibody to measles, mumps and rubella (German measles) viruses to compare the longevity of antibody response to these vaccines or natural infection to the antibody response to the hepatitis B vaccine or natural infection. The results of this study will help to answer the question whether a booster vaccination is required and at which time after the primary vaccination course it should be considered.

• INCLUSION CRITERIA:

• Age 18 years or above and < 60 years when the first dose of hepatitis B vaccine was administered
• Male or female
• Vaccination with 3 doses of either plasma-derived or recombinant HBV vaccine within one year (with the exception of the 10 patients who were never vaccinated and never infected with the hepatitis B virus)
• Vaccinated subjects must be able to provide written documentation indicating the dates of their hepatitis B immunization series. In the absence of written documentation, subjects will be asked to sign a written affidavit obtained either from themselves or their physician stating the date of vaccination accurate to one year and that they did not receive a booster dose to the best of their knowledge.
• For recovered patients, spontaneous recovery from acute hepatitis B must have occurred prior to the year 2000
• Willing and able to provide written, informed consent

Additional Inclusion Criteria for HIV positive cohort

• CD4 count of great than or equal to 250 /mm3 at time of vaccination
• Known HIV infection at time of vaccination

Exclusion criteria

• History of chronic HBV infection
• Incomplete HBV vaccine doses (with the exception of the 10 patients who were never vaccinated and never infected with the hepatitis B virus)
• Known non-response to an adequate course of hepatitis B vaccine
• Received a booster dose of HBV vaccine
• Current or recent (within the last 1 year) use of immunosuppressive/immuno-modifying agents
• Use of immunosuppressive/immuno-modifying agents at the time of vaccination
• Renal failure with requirement for dialysis
• Anti-HIV positive (Except for HIV positive cohort)
• Anti-HCV positive
• History of bone marrow or stem cell transplant
• History of organ transplant
• Known underlying immune suppressive condition
• Subjects with clinically significant anemia, hemoglobin <10g/dL will be excluded from participating in the assessment of response to a booster dose of HBV vaccine until their hemoglobin is greater than or equal to12g/dL.
• Anti-HBc positivity for the 10 patients who were never vaccinated and never infected with the hepatitis B virus.