Efficacy of Hepatitis B Vaccination in Under Five-Year-Old Children in Iran: A Systematic Review and Meta-Analysis Study

Context: Hepatitis B viral infection, specially in children, is an unsolved global health issue. National and international vaccination programs, as the main means to prevent this infection, have been operating for years. This meta-analysis study was launched to investigate the vaccination efficacy in under five-year-old children in Iran. Evidence Acquisition: In this research, all national databases including, SID, Magiran, Iran medex, Iran doc, and Medlib, as well as international databases, including PubMed, Medline, and ISI were searched for published articles associated with evaluation of seroconversion rates after hepatitis-B vaccination in Iranian children. The search was performed in the Persian and/or English language and in under five-year-old children in Iran. The variance of each study was calculated using the binomial distribution formula. The results of studies were combined using random-effects meta-analysis model. Data were analyzed using STATA version 12. Results: In the present research, 11 studies, performed from 2000 to 2017, were investigated. The number of samples in these 11 studies were 3063 children (1592 males and 1471 females). In the studies, the efficacy range of the hepatitis-B vaccine in under five-year-old children in Iran was 89 (95 CI: 86 -93) with high heterogeneity (P value for heterogeneity was 0.001, I-2 = 92.9). Range of efficacy for males and females was 85 (95 CI: 78 to 91) and 88 (95 CI: 83 to 93), respectively. Conclusions: The hepatitis B virus (HBV) vaccination program in Iran seems to be highly effective although some questions, such as the effect of gender on responsiveness to vaccine and heterogeneity of different data, remain unclear.