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.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. detection of hbv dna in the absence of a detectable hbsag level and occasionally other hbv serologic markers is termed occult hepatitis b (ohb).