Two decades of hepatitis B vaccination in mentally retarded patients: effectiveness, antibody persistence and duration of immune memory.
BACKGROUND
Institutionalized mentally retarded subjects are well-known to be at-risk for HBV infection. We studied the persistence of vaccine-induced anti-HBs antibodies and the robustness of the HBsAg-specific immune memory in this population, 18-20 years after the first vaccine dose.


METHODS
Non-immune residents of 4 institutions were immunized in 1984-1986. In 2004, 207 subjects were bled to determine humoral and cellular immune memory. Immune response to a booster dose was evaluated in subjects with anti-HBs level <100 IU/L.


RESULTS
Four subjects showed anti-HBc seroconversion, without clinical implications. Pre-booster anti-HBs levels <100 IU/L were found in 45 subjects (22%); 34/39 (87%) responded with a rapid and high anti-HBs titer to the booster dose. Robust T and B cell memory was present pre- and post-booster.


CONCLUSIONS
Overall results confirm that hepatitis B vaccines are highly effective and immunogenic, and confer long-term persistence of antibodies and immune memory in an at-risk population.
Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute, Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610 Antwerpen (Wilrijk), Belgium. tessa.braeckman@ua.ac.be
Tessa
T
Braeckman
Koen
K
Van Herck
Wolfgang
W
Jilg
Tanja
T
Bauer
Pierre
P
Van Damme
D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000276:immunology; D005260:Female; D006510:Hepatitis B Antibodies / Q000097:blood*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage*; D006801:Humans; D007111:Immunity, Cellular; D007117:Immunization, Secondary; D007156:Immunologic Memory; D007326:Institutionalization; D008297:Male; D008875:Middle Aged; D019989:Persons with Intellectual Disabilities / Q000706:statistics & numerical data*; D013601:T-Lymphocytes / Q000276:immunology; D055815:Young Adult
D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines