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Detection of hepatitis B surface gene mutation in carrier children with or without immunoprophylaxis at birth
Insights
Hepatitis B virus (HBV) immunoprophylaxis may select for mutant strains. Vaccinated children showed mutations in the HBV surface gene, suggesting immune pressure drives viral evolution.
Area of Science:
- Virology
- Immunology
- Genetics
Background:
- Hepatitis B virus (HBV) infection is a global health concern.
- Understanding HBV genetic variations is crucial for effective prevention and treatment.
Purpose of the Study:
- To investigate the clinical significance of mutations in the hepatitis B virus (HBV) surface gene.
- To analyze the impact of immunoprophylaxis on HBV mutation selection.
Main Methods:
- DNA sequence analysis of the HBV "a" determinant region.
- Sera samples from 27 vaccinated carrier children, their mothers, and 21 unvaccinated carriers were analyzed.
Main Results:
- Precore mutant (G to A at nucleotide 1896) detected in 11 unvaccinated carriers.
- Mutations in the "a" determinant found in 6 (22%) vaccinated children.
- Specific mutations included Gly-to-Arg at codon 145 and substitutions at amino acids 133 and 144.
Conclusions:
- Immune pressure from immunoprophylaxis at birth may select for mutant HBV strains.
- This selection pressure can lead to the emergence of specific viral variants in vaccinated populations.
Abstract:
To investigate the clinical significance of mutation in hepatitis B virus (HBV) surface gene, DNA sequence analysis of the "a" determinant was performed on sera from 27 carrier children with immunoprophylaxis, their mothers, and 21 carriers without vaccination. A precore mutant (G to A) at nucleotide 1896 was detected in sera from 11 carriers without vaccination. Mutations in the "a" determinant were detected in 6 (22%) of the vaccinated children. Four HBV strains showed a Gly-to-Arg mutation at the 145th codon of the surface gene. Amino acid substitutions at amino acid 133 and 144 were noted in the other 2 children. Only 1 mother had the same predominant strain of mutant virus as her child. These observations indicate that immune pressure exerted by immunoprophylaxis at birth may select for a mutant virus.