Long-term persistence of anti-HBs after vaccination against HBV: an 18 year experience in health care workers.

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.

Occupational risk of blood-borne viruses in healthcare workers: a 5-year surveillance program.

OBJECTIVE: This study presents the results of a 5-year surveillance program involving the prospective follow-up of healthcare workers (HCWs) in the Veneto region of Italy exposed to blood-borne viruses. DESIGN: All HCWs who reported an occupational exposure to blood-borne infection joined the surveillance program. Both HCWs and patients were tested for viral markers (hepatitis B surface antigen [HBsAg], antibody to hepatitis B surface antigen [anti-HBs], antibody to hepatitis B core antigen [anti-HBc], antibody to hepatitis C virus [anti-HCV], HCV RNA, and antibody to human immunodeficiency virus [HIV]) and had these markers plus transaminases assayed at 3, 6, and 12 months and then yearly thereafter. Moreover, a program of hepatitis B virus (HBV) prophylaxis was offered to those whose anti-HBs levels were less than 10 IU/mL. PARTICIPANTS: Two hundred forty-five HCWs (156 women and 89 men) with a mean age of 37 (+/- 10) years who reported occupational exposure during the 5-year period. RESULTS: At the time of exposure, 1 HCW was positive for HBsAg (0.4%) and 2 were positive for HCV RNA (0.8%). Among the patients involved, 28 (11.4%) were positive for HBsAg, 68 (27.8%) were positive for HCV RNA, 6 (2.4%) were positive for HIV, and 147 (60.0%) were negative for all viral markers (4 patients were positive for both HCV and HIV). During the follow-up period after exposure (mean, 2.7 [+/- 1.6] years), there was no increase in transaminases or seroconversions to any of the viral markers. CONCLUSION: Our accurate postexposure follow-up revealed a lack of transmission of HBV, HCV, and HIV.