Persistence of anti-HBs antibody in children whom vaccinated during infantile period and need to booster needs more discussion

Abstract

Sir,The published article by Aypak et al. [1] focused on thepersistence of anti-HBs antibody (Ab) in 2- to 12-year-oldchildren in Turkey and the high titer of anti-HBs antibody in94 (52.8 %) of whom were anti-HBs antibody negative afterboosting HBV vaccination [1]. There is a recent report byTosun et al. from Turkey [4] that they found protective levelof antibody near 50 % in children after 9 years of neonatalvaccination. The reported rate of persistent protective levelof anti-HBs Ab titers varied from 33 up to 79 %, at least5 years after vaccination [5].It seems that the differences arerelated to the possibility of enrollment of some childrenwithout complete vaccination or related to maintaining coldchain in transportation and handling of vaccine, improperinjection, and other technical problems [3]. Following acomplete series of vaccination during neonatal period, pro-tective antibody level raises in more than 95 % of infants upto 18 months after vaccination, but we do not have enoughdata to confirm the response or non-response to HBV vac-cine in the enrolled study group in the study of Aypak et al.that the main cause is related to retrospective pattern of thestudy. There is a possibility of previous HBV infection thatmight potentially be responsible for non-responsiveness toHBV vaccine. In the study of Aypak et al., there is around50 % missing outcome in who were anti-HBs antibodynegative. However, I would like to emphasize that in chang-ing the epidemiology of HBV transmission from vertical tohorizontal during adolescence, we should consider thetesting of anti-HBs Ab during this period to make sure thepersistence of long-lasting immunity extending to adult-hood. Finally, I would like to add that celiac disease maybe associated with non-response to HBV vaccine and eval-uation of non-responder is recommended [2].