Immune response to hepatitis B vaccine in patients who lost hepatitis B surface antigen during follow up

We read with interest the article by Taheri et al. regarding the efficacy of Hepatitis B vaccine in those who lost Hepatitis B surface antigen (HbsAg) during follow up (1). As the authors mentioned, a protective anti-HBs level developed in 24% of chronic HBsAg-positive subjects who had already lost their HBsAg after hepatitis B vaccination, and the remaining cases need to be monitored for occult HBV infection. Subjects with no response after hepatitis B vaccination may have low levels of HBsAg or have immunologic tolerance to hepatitis B vaccination and no ability to produce anti-HBs antibody as reported previously (2). Detection of HBV DNA in the absence of a detectable HBsAg level and occasionally other HBV serologic markers is termed occult hepatitis B (OHB) (3). These patients can not only transmit HBV to others but also may progress to chronic hepatitis, cirrhosis, and hepatocellular carcinoma. The prevalence and outcomes of OHB in chronic HBV-infected individuals have not yet been rec 2011 Kowsar M.P.Co. All rights reserved. Please cite this paper as: Zacharakis G, Viazis N, Karamanolis DG. Immune response to hepatitis B vaccine in patients who lost hepatitis B surface antigen during follow up. Hepat Mon.2011;11(6):481-2.