1. The effect of introduction of universal childhood hepatitis B immunization in South Africa on the prevalence of serologically negative hepatitis B virus infection and the selection of immune escape variants.
- Author
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Hino K, Katoh Y, Vardas E, Sim J, Okita K, and Carman WF
- Subjects
- Amino Acid Sequence, Antigenic Variation, Base Sequence, Child, Preschool, Cohort Studies, DNA Primers genetics, Genes, Viral, Hepatitis B immunology, Hepatitis B virology, Hepatitis B Antibodies blood, Hepatitis B Surface Antigens blood, Hepatitis B Surface Antigens genetics, Hepatitis B Surface Antigens immunology, Hepatitis B virus genetics, Hepatitis B virus immunology, Humans, Infant, Molecular Sequence Data, Polymerase Chain Reaction statistics & numerical data, Sensitivity and Specificity, South Africa epidemiology, Hepatitis B epidemiology, Hepatitis B prevention & control, Hepatitis B Vaccines pharmacology
- Abstract
The effect of universal hepatitis B vaccination on the prevalence of serologically negative hepatitis B virus infection (HBV) and the emergence of HBsAg variants is unknown. We prospectively studied two different cohorts of 12--24 month old children in South Africa. They consisted of the unvaccinated children (n=459) born before the introduction of universal vaccination and the vaccinated children (n=1213) between 1 and 2 years after the introduction of the vaccination program. The frequency of detecting HBV DNA by PCR was reduced from 6.5% in unvaccinated children to 0.3% in vaccinated children (P<0.00001). There were no unique amino acid substitutions within the major hydrophilic region of the S sequence in both pre- and post-vaccination samples. Universal childhood vaccination reduced the frequency of serologically negative HBV infection and did not necessarily lead to selection of escape variants.
- Published
- 2001
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