Immune response to second vaccination series of hepatitis B virus among booster dose non-responders.

Abstract Objective To evaluate the response to second vaccination series among post-booster sero-negative children who had previously received compulsory HBV vaccination. Subjects and methods After given a booster dose to 1070 children, 103 of them failed to generate anamnestic response (anti-HBs nd vaccination series) after 1 and 6 months post-booster. Blood sample was withdrawn aseptically one month later for quantitative assessment of anti-HBs to detect development of protective immune response (≥10 IU/L). Immunological vaccination failure was assigned to children who did not develop protective immune response after 2 nd vaccination series. Results Protective immune response was detected among 84/91 children (92.3%). While 7/91 (7.7%) whose age were ≥10 years did not respond and had post-booster undetectable anti-HBs. About 80% of children with post-booster detectable anti-HBs showed significant protective immune response (anti-HBs ≥100 IU/L) and higher GMT (299.1 ± 3.6 IU/L) compared to those with undetectable 60% and 106.2 ± 12.9 IU/L respectively ( P P  > 0.05. All children with history of rheumatic fever (7 children) or diabetes mellitus (1 child) developed immune response after 2 nd vaccination series. Conclusion A booster dose of HB vaccine may be unable to induce sufficient immunological response in children who had undetectable anti-HBs titers. Revaccination for non-responders is an important procedure to increase HBV protection rate.