Abstract：
Hepatitis B virus (HBV) vaccine is composed of the purified hepatitis B surface antigen (HBsAg) that is produced by recombinant DNA technology. The neutralizing antibodies induced by vaccination target mainly the \"a\" determinant, aa124-147, of the outer viral envelope (HBsAg). In the present work, we demonstrate a case study for vaccinated patient that is infected with a vaccine escape HBV strain (Eg200). Characterization of the isolate Eg200 showed that it belongs to the genotype D and an uncommon sub-genotype in Egypt; D9. The DNA sequence encoding HBsAg was sequenced. Mutational analysis of the HBsAg showed a double mutation in the \"a\" determinant of this HBV isolate; T125M and P127T. However, such substitutions were found to be conserved to the detected serotype, ayw3, of Eg200 isolate. This case report indicates that continuous characterization of breakthrough vaccine escape strains of HBV is essential to develop the immunization strategies against HBV infection.
摘要：
乙型肝炎病毒（HBV）疫苗由重组DNA技术产生的纯化的乙型肝炎表面抗原（HBsAg）组成。疫苗接种诱导的中和抗体主要针对“a”决定因素，aa124-147，外病毒包膜（HBsAg）。在目前的工作中,我们展示了一个针对接种疫苗的患者的案例研究，该患者感染了疫苗逃逸HBV株（Eg200）。分离株Eg200的表征表明，它属于基因型D，在埃及是一种罕见的亚基因型；D9。对编码HBsAg的DNA序列进行测序。对HBsAg的突变分析显示该HBV分离株的“a”决定子的双突变;T125M和P127T。然而,发现此类替换与检测到的血清型保守，ayw3，为Eg200分离株。此病例报告表明，持续表征的突破疫苗逃逸株的HBV是必不可少的，以制定针对HBV感染的免疫策略。
