Evaluation of the Efficacy of Hepatitis B Vaccine in Different Age Groups of Immunized Children in Gaza Strip

Abstract

The objective of this study is to evaluate the long-term efficacy of infant hepatitis B immunization program in Gaza strip on preventing hepatitis B virus infection, and assess its impact on the incidence of hepatitis B in children. The participants in this study were 180 children, 90 males and 90 females categorized into three age groups (2 - 5y), (6 - 8y) and (9 -11y). Serum samples for each participant were tested for the quantitative determination of anti-HBs antibody using microparticle enzyme immunoassay (MEIA) technology as well as immunochromatographic qualitative testing for HBs Ag. The study showed that the efficacy of hepatitis B vaccine is 98.3% . HBs Ag was not detected in any participant. The protective rates for the (2 - 5y) and (6 - 8y) groups were 100% while the protective rate for the (9 - 11y) group was 95% (P 0.04). Also the study showed that the efficacy of hepatitis B vaccine was statistically significant among the three age groups (P < 0.04), especially between (2 - 5y) group and (9 - 11y) group, also between (2 - 5y) group and (6 - 8y). The results of this study revealed that there was no significant difference between males and females for hepatitis B vaccine efficacy (P > 0.05). We concluded that the hepatitis B vaccine efficacy is high in immunocomptent population and a booster dose is not necessary at least in the stodied age groups, due to the existence of an anamenstic response.