Effect of Revaccination with Recombinant Hepatitis B Virus Vaccine Containing Higher Antigen Concentration in Non-responder Children

BACKGROUND: Hepatitis B is a global health problem carrying significant morbidity and mortality. Vaccination against hepatitis B virus (HBV) has been implemented with good effectiveness, but a small proportion of children do not respond well after complete routine vaccination. They are called non-responders and are at higher risk for HBV infection. AIM: The objective of the study was to determine the effect of revaccination with recombinant HBV vaccine containing higher antigen concentration in non-responder children. METHODS: A prospective study was conducted from January 2018 until December 2019. Inclusion criteria were children aged 9–15 months and had three doses of recombinant HBV at 0, 1, and 6 months old. Exclusion criteria were the presence of acute or chronic hepatitis B and conditions which alter immune function and immunosuppressant medications consumption. Demographic and clinical characteristics were gathered from each subject along with serum HBsAb titer examination. Subjects with serum anti-hepatitis B surface antigen (HBsAb) titer of <10 IU/L were classified into non-responders and underwent revaccination with 3 doses of vaccine containing 20 μg HBsAg. The revaccination series was repeated until all subjects showed seroconversion. After each series, repeated serum HBsAb titer measurements were conducted. RESULTS: A total of 400 children were enrolled in this study with a mean age of 12.1 (SD 2.64) months. Subjects were dominated with females (54.0) and normal nutritional status (79.0). The rate of non-responsiveness was 9.0%. Of all non-responders, 88.9% experienced seroconversion after the first revaccination series. After the third revaccination series, all subjects had serum HBsAb titer at the protective level. CONCLUSION: Revaccination with recombinant HBV vaccine containing higher antigen concentration in non-responder children is effective.