title: Hepatitis B vaccination of adolescents: significance of non-protective antibodies.
abstract: Despite hepatitis B virus (HBV) immunization, a percentage of healthy individuals display an antibody titre below the threshold for clinical protection (10 IU/L). In order to predict the existence of this inducible immunological response, the precise anti-HBs titre required to achieve protection in immunized patients with waned HBs antibodies must first be determined. A total of 4486 vaccinated students attending the University of Padova Medical, Science, and Veterinary School were recruited for study between 2004 and early 2012. The baseline concentration of anti-HBs was measured at enrolment. Participants displaying anti-HBs titre < 10 IU/L at the follow-up examination (mean 10.8 years) were given a booster vaccination and retested 20-30 days later. At enrolment, 87.6% of the 4486 vaccinated subjects showed persistence of anti-HBs higher than 10 IU/L. Of the 279 booster-vaccinated subjects, 94.6% achieved the cut-off titre. Booster-induced immunological response was correlated to the pre-booster titre level, with ≥ 2 IU/L ensuring a robust positive response and less than 2 IU/L being associated with the probability of developing insufficient levels of antibodies. Pre-booster antibody titre higher than 2 IU/L in adults might be predictive of an anamnestic response to booster vaccination, whereas titres below this value may indicate likelihood of non-response.
authors.affiliation: Department of Molecular Medicine, University of Padova, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Chiara
authors.affiliation: Department of Molecular Medicine, University of Padova, Italy.
authors.forename: Giovanni Battista
authors.initials: GB
authors.lastname: Bartolucci
authors.affiliation: Department of Molecular Medicine, University of Padova, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Cattai
authors.affiliation: Department of Molecular Medicine, University of Padova, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Piazza
authors.affiliation: Department of Molecular Medicine, University of Padova, Italy.
authors.forename: Annamaria
authors.initials: A
authors.lastname: Nicolli
authors.affiliation: Department of Molecular Medicine, University of Padova, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Buja
authors.affiliation: Department of Molecular Medicine, University of Padova, Italy. Electronic address: andrea.trevisan@unipd.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Trevisan
mesh_terms: D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006509:Hepatitis B / Q000276:immunology* / Q000517:prevention & control*; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006515:Hepatitis B virus / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D008297:Male; D012372:ROC Curve; D014611:Vaccination; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D017325:Hepatitis B Vaccines
keywords: Anti-HBs; Booster vaccination; Hepatitis B; Persistence of antibodies; Protective antibodies; Vaccination