title: Immune memory response induced in vitro by recombinant hepatitis B surface antigen challenge 13-18 years after primary vaccination.
abstract: The question of whether booster doses are required to maintain long-term protection against hepatitis B virus (HBV) after primary vaccination remains to be determined. Thus, the aim of this study was to evaluate the immune memory responses to hepatitis B surface antigen (HBsAg) challenge in vaccinated individuals through an in vitro-specific stimulation assay. Peripheral blood mononuclear cells (4 × 10(6)  cells/ml) were stimulated with 50 ng/ml of recombinant HBsAg. In vitro anamnestic antibody responses, as shown by detection of high avidity antibody in culture supernatants, were found 13-18 years after primary vaccination and were not correlated with serum antibodies (r = -0.177; P = 0.377). In addition, the findings from this study indicate that immune memory against hepatitis B was well preserved in 40.0% and 60.0% of vaccinees with anti-HBs levels less than 10 IU/L or lacking serum antibodies altogether, respectively. In conclusion, the data suggest the presence of immunological memory in vaccinated individuals, including those who showed anti-HBs <10 IU/L or undetectable antibody.
authors.affiliation: Post-Graduation Program in Pharmacy, Health Sciences Center, Federal University of Santa Catarina, University Campus, Florianópolis, Santa Catarina, Brazil.
authors.forename: Andréa
authors.initials: A
authors.lastname: do Livramento
authors.forename: Júnia
authors.initials: J
authors.lastname: Schultz
authors.forename: Keila Zaniboni Siqueira
authors.initials: KZ
authors.lastname: Batista
authors.forename: Arício
authors.initials: A
authors.lastname: Treitinger
authors.forename: Caio Maurício Mendes
authors.initials: CM
authors.lastname: de Cordova
authors.forename: Celso
authors.initials: C
authors.lastname: Spada
mesh_terms: D000293:Adolescent; D000328:Adult; D000915:Antibody Affinity; D005260:Female; D006510:Hepatitis B Antibodies / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000235:genetics / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D007156:Immunologic Memory; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D055815:Young Adult
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D011994:Recombinant Proteins
keywords: HBV; anamnestic response; immunity