The hepatitis B vaccine protects re-exposed health care workers, but does not provide sterilizing immunity. 

<br/><br/>Available online from MWHC library: 1995 - present, Available in print through MWHC library: 1996 - present 
<br/><br/> BACKGROUND & AIMS: Infection with hepatitis B virus (HBV) can be prevented by vaccination with HB surface (HBs) antigen, which induces HBs-specific antibodies and T cells. However, the duration of vaccine-induced protective immunity is poorly defined for health care workers who were vaccinated as adults.  CONCLUSIONS: HBs antigen vaccine-induced immunity protects against future infection but does not provide sterilizing immunity, as evidenced by HBcore- and polymerase-specific CD8(+) T cells in vaccinated health care workers with occupational exposure to HBV. The presence of HBcore- and HBV polymerase-specific T-cell responses is a more sensitive indicator of HBV exposure than detection of HBcore-specific antibodies. Copyright  2013 AGA Institute. Published by Elsevier Inc. All rights reserved.  METHODS: We investigated the immune mechanisms (antibody and T-cell responses) of long-term protection by the HBV vaccine in 90 health care workers with or without occupational exposure to HBV, 10-28 years after vaccination.  RESULTS: Fifty-nine of 90 health care workers (65%) had levels of antibodies to HBs antigen above the cut-off (>12 mIU/mL) and 30 of 90 (33%) had HBs-specific T cells that produced interferon-gamma. Titers of antibodies to HBs antigen correlated with numbers of HBs-specific interferon-gamma-producing T cells, but not with time after vaccination. Although occupational exposure to HBV after vaccination did not induce antibodies to the HBV core protein (HBcore), the standard biomarker for HBV infection, CD4(+) and CD8(+) T cells against HBcore and polymerase antigens were detected. Similar numbers of HBcore- and polymerase-specific CD4(+) and CD8(+) T cells were detected in health care workers with occupational exposure to HBV and in patients who acquired immunity via HBV infection. Most of the HBcore- and polymerase-specific T cells were CD45RO(+)CCR7(-)CD127(-) effector memory cells in exposed health care workers and in patients with acquired immunity. In contrast, most of the vaccine-induced HBs-specific T cells were CD45RO(-)CCR7(-)CD127(-) terminally differentiated cells. 
<br/><br/><br/>English 
<br/><br/><label>ISSN: </label>0016-5085 
<br/><br/><label>Subjects--Topical Terms: </label><br/>*Health Personnel<br/>*Hepatitis B Vaccines/tu [Therapeutic Use]<br/>*Hepatitis B/pc [Prevention & Control]<br/>*Immunity/im [Immunology]<br/>*Infectious Disease Transmission, Professional-to-Patient/pc [Prevention & Control]<br/>*Occupational Exposure<br/>Adult<br/>Aged<br/>Antibodies, Viral/bl [Blood]<br/>Antibodies, Viral/im [Immunology]<br/>CD8-Positive T-Lymphocytes/im [Immunology]<br/>CD8-Positive T-Lymphocytes/pa [Pathology]<br/>Female<br/>Hepatitis B Surface Antigens/bl [Blood]<br/>Hepatitis B Surface Antigens/im [Immunology]<br/>Hepatitis B Vaccines/im [Immunology]<br/>Hepatitis B virus/im [Immunology]<br/>Hepatitis B/im [Immunology]<br/>Humans<br/>Longitudinal Studies<br/>Male<br/>Middle Aged<br/>Time Factors
<br/><br/><label>Subjects--Geographic Terms: </label><br/>MedStar Washington Hospital Center
<br/><br/><label>Index Terms--Occupation: </label><br/>Medicine/Gastroenterology
<br/><br/><label>Index Terms--Function: </label><br/>Comparative Study<br/>Journal Article<br/>Research Support, N.I.H., Intramural<br/>Research Support, Non-U.S. Gov't