Immunity to hepatitis B vaccine among health care workers.

The aim of this study was to determine the level of anti-HBsAg (hepatitis B surface antigen) in vaccinated high risk group. We measured anti-HBsAg concentration in blood sera of adult students aged from 19 to 37 years old. Five milliliters (5ml) of blood sample was taken from 210 cases four months after the second dose and 126 out of 210 cases three months after the third dose of hepatitis B vaccination. All blood samples were analyzed for anti-HBsAg by ELISA method. 125 out of 210 samples (59.5%) showed anti-HBsAg concentrations higher than 20mIu/ml and considered immune after the second dose of hepatitis B vaccination. Also, 99.2% of samples had anti-HBsAg higher than 20mIu/ml three months after the third dose of the vaccination. Non-immune cases in males were more than females (41.2% vs.40.1%). In conclusions, our results reinforce the importance of hepatitis B vaccine in adolescents and suggest that three dose of hepatitis B vaccine is necessary to increase the seropositive rate of anti-HBsAg in adults.