title: Long-term persistence of anti-HBs after vaccination against HBV: an 18 year experience in health care workers.
abstract: The aim of the present study was to evaluate the long-term persistence of seroprotection after hepatitis B virus (HBV) vaccination. A total of 422 health care workers (HCWs) were evaluated 4.8-18.8 years after primary immunization (mean follow-up 11.8 years); 241 of them had received plasma-derived vaccines and 181 had been given yeast-derived vaccines; 107 subjects received a booster dose of yeast-derived vaccine 6 years after primary immunization with either plasma-derived or yeast-derived vaccines. Seroprotection was assumed when the anti-HBs titers were >10 mIU/ml. The overall response after primary immunization was 98.8%. Among subjects who reached a 10 year follow-up, those treated with plasma-derived vaccine had a seroprotection rate of 87.8 compared to 81.6% of those vaccinated with yeast-derived vaccines (P<0.001). Anti-HBs geometric mean titers (GMTs) after primary immunization were similar in the two groups, but were significantly lower at 10 years follow-up in the group that had received a yeast-derived vaccine (104 mIU/ml versus 244 mIU/ml in those who used a plasma-derived vaccine, P<0.05). Anti-HBs GMTs in the 107 subjects given the booster dose were 242 mIU/ml pre-booster titer, and rose to 35,171 mIU/ml after the booster dose. A mean 10.1 years after the booster dose, GMTs were 952 mIU/ml. Overall, the anti-HBs seroprotection rate was 95.4% (102 subjects). Based on GMT results, no booster dose is necessary in healthy adults for at least 10 years after primary immunization.
authors.affiliation: Department of Surgical and Gastroenterological Sciences, University of Padua, Via Giustiniani 2, 35128 Padua, Italy. annarosa.floreani@unipd.it
authors.forename: Annarosa
authors.initials: A
authors.lastname: Floreani
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Baldo
authors.forename: Marco
authors.initials: M
authors.lastname: Cristofoletti
authors.forename: Giovanni
authors.initials: G
authors.lastname: Renzulli
authors.forename: Antonio
authors.initials: A
authors.lastname: Valeri
authors.forename: Caterina
authors.initials: C
authors.lastname: Zanetti
authors.forename: Renzo
authors.initials: R
authors.lastname: Trivello
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006282:Health Personnel; D006510:Hepatitis B Antibodies / Q000032:analysis*; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007156:Immunologic Memory; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D012727:Sex Characteristics; D013997:Time Factors; D014611:Vaccination
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines