The effects of anti-HBs antibodies passed through transplacental route on immunization induced by HBV vaccine and natural course of passively transmitted HBs antibodies

Introduction: Hepatitis B infection is an important infection that concerns public health. In this study, we aimed to evaluate whether anti-Hbs antibodies born from mothers who are immune to hepatitis B virus with natural or vaccination and passed from mother to baby transplacentally affect the natural course of these passive anti-HBs antibody titers. Methods: In this study, 68 healthy term newborn babies were included. The immune status of the mothers of these newborn babies was evaluated. Babies were divided into three groups. Group 1, babies whose mothers were positive for AntiHBs antibody, anti-HBS titers were evaluated consecutively at 0, 1, 3, 6 and 8 months without HBV vaccine. In Group 2, babies whose mothers were positive for anti-HBs antibody were vaccinated with HBV vaccine at 0.1 and 6 months, and these babies were examined for anti-HBS titers at 0.1, 3, 6 and 8 months. In Group 3, babies whose mothers were negative of anti-HBs antibody were vaccinated with HBV vaccine at 0, 1 and 6 months, and babies were examined at 0.1, 3, 6 and 8 months. Results: Group 1 consisted of 22 babies, Group 2 consisted of 24 babies and Group 3 consisted of 22 babies. Percentages of anti-HBs titers falling below <10 mIU/mL at 1, 3, 6 and 8 months were found to be 40.9%, 50%, 59.09%, and 100% of nonvaccinated babies whose mothers were positive for anti-HBs antibody. Discussion and Conclusion: We found that the antibody response to HBV vaccine administered to infants with passive antibodies was similar to the antibody response in mothers vaccinated with their mothers HBsAg (-), anti-HBs (-), anti-HBcIgM (-) and the same vaccine calendar. Thus, it was found that anti-HBs antibodies that started this transplacentalntal pathway did not affect the antibody response produced by the HBV vaccine administered at 0, 1 and 6 months