Effect of Vaccination Against Hepatitis B in Cases with Isolated Anti-HBc

1.3% of people in Iran are positive for anti-HBc antibody.The objective of this study is to determine the rate of seroconversion in those with persistent isolated anti-HBc after vaccination. In a quasi-experimental study, 94 persons with isolated anti-HBc antibody who were referred to Tehran Blood Transfusion Organization between 2002 and 2004 were selected through a convenient sampling. They were given recombinant hepatitis B vaccine on 0, 1 and 6 months. Immunization was defined by anti-HBs antibody titer |≥|10 mIU/mL, 1-2 months after administration of the last dose. Response to HB vaccination consisted of 28%, 62% and 76% after each injection, respectively. The total response rate was 80% (n=75). Nineteen (20%) persons were negative for anti-HBs even after three doses of HB vaccination. Factors associated with decreased response to vaccination were positive anti-HBe (OR=6.4, P=0.008), history of bloodletting (OR=3.1, P=0.039) and prior history of being HBsAg positive (OR=5.6, P=0.002). Although there were some differences between the response rates after each vaccine injections observed in our study and similar ones, the total response was nearly the same.