| Abstrakt: |
Background: Hepatitis B virus (HBV) vaccination was one of the success stories of the 20th. Century. It is highly effective and safe and was incorporated into national immunization programs of countries worldwide. Objectives: To explore the response rate and titers of anti-HBs antibodies among children 1-14 years old immunized with HB vaccine in Baquba city Diyala province. Vaccinees and Methods: This cross sectional study was conducted in Baquba City, the center of Diyala province-Iraq for the period 20 July/2016 to 20 March/2017. A total of 452 children were enrolled, 247 (54.6%) were males and 205 (45.4%) were females, with an age range of 1- 14 years. All were previously immunized with genetically engineered HBV vaccine (Euvax B, Korea), with a dose of 10 micrograms of HBsAg/0.5 milliliter (children vial) intramuscularly. Venous blood samples were collected aseptically; sera were separated and subjected for the detection of HBsAg, anti-HBs antibody titer, HBe Ag and total antibody and anti-HBc total antibody using Enzyme Linked Immunosorbant assays (ACON, Foresight-USA). A pre-constructed questionnaire form was prepared including information of socio-demographic, health, and vaccination status. Statistical analysis was done using the Statistical Package for Social Science (SPSS), Version 23. P values < 0.05 were considered significant. Results: The overall anti-HBs Ab positivity rate was 75.66% (95% CI was 71.5% - 79.6%), with a mean anti-HBs Ab titers range (10.1 - 673.4 mIU/ml). However, the titer was failed to reach the protective level in 110 (24.34%) vaccinees. The highest anti-HBs Ab positivity rate among children administered 1or 2 vaccine dose is significantly higher among those after <1 year duration (80.0%, P = 0.043), while the mean anti-HBs Ab titer is insignificantly highest among same group of children (43.7 mIU/ml, P = 0.24). The highest anti-HBs Ab positivity rate among children administered 3 vaccine doses is significantly higher among those after <1 year duration (91.3%, P = 0.003), and similarly the highest mean of anti-HBs Ab titer is insignificant higher among the same children group (81.3 IU/ml, P = 0.2). Regarding those children received 4 vaccine doses, the anti-HBs Ab positivity rate and the mean anti-HBs Ab titer are significantly higher among children after <1 year (89.9%, P = 0.004 and 97.7 IU/ml, P < 0.001) respectively. Finally, the anti-HBs Ab positivity rate after 5 vaccine doses was insignificantly higher after 1-3 year duration (72.4%, P = 0.15), while the highest mean anti- HBs Ab titer was significantly higher among those with less than one year duration (55.0 IU/ml, P < 0.041). Conclusion: Universal HB vaccination is generally produce high rate of protection among children and the highest anti-HBs Ab titer was achieved through 3 or 4 doses after less than one year post vaccination. [ABSTRACT FROM AUTHOR] |
