接种乙型肝炎疫苗后HBsAg携带者病毒基因S区“a”决定簇变异

Study on HBV DNA “a” deteminant mutation in viral carrier children following universal HB vaccination

目的 探讨乙型肝炎疫苗普种后人群HBVDNA基因组S区“a”决定簇的变异率。方法 对 72例疫苗接种后HBsAg携带者HBVDNA基因组S区“a”决定簇进行了序列分析。结果 在4例小儿血清中发现有 145Arg、140Ile和 12 6Ser变异株各 1例 ,12 6Ser变异株与野毒株混合感染 1例 ,变异率为 5 .5 6 %。同时发现近 30年来我国乙型肝炎病毒亚型发生了明显的变迁。结论 疫苗接种可能会引起病毒变异 ,且现有疫苗不能预防变异株感染及变异株可能发生传播。

Objective To investigate hepatitis B virus mutation rate after the universal immunization in China. Methods DNA sequence analysis of the “a” determinant was performed on sera from 72 viral carrier children after immunoprophylaxis selected through a sampling survery. Results Four mutants were detected, the mutation rate was 5.56%. One strain showed Gly-to-Arg mutation at the 145 codon of surface antigen. Animo acid substitutions at the amino acid 126 and 140 were noted in the other three children. The epidemiological HBV serotype shifted from previous adw infection to more recent adr was also observed. Conclusions These observations indicate that vaccination is probably the cause of mutation, whereas the mutation is low and it will certainly not be a reason for doubting that the vaccination is the method of main choice for preventing hepatitis B infection that still devastates the developing countries.