title: 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.
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.
authors: First Department of Internal Medicine, School of Medicine, Yamaguchi University, 1-1-1 Minami Kogushi, Ube, Yamaguchi 755-8505, Japan. k.hino@po.cc.yamaguchi-u.ac.jp
authors: K
authors: K
authors: Hino
authors: Y
authors: Y
authors: Katoh
authors: E
authors: E
authors: Vardas
authors: J
authors: J
authors: Sim
authors: K
authors: K
authors: Okita
authors: W F
authors: WF
authors: Carman
mesh_terms: D000595:Amino Acid Sequence; D000940:Antigenic Variation; D001483:Base Sequence; D002675:Child, Preschool; D015331:Cohort Studies; D017931:DNA Primers / Q000235:genetics; D005814:Genes, Viral; D006509:Hepatitis B / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood / Q000235:genetics / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000494:pharmacology*; D006515:Hepatitis B virus / Q000235:genetics / Q000276:immunology; D006801:Humans; D007223:Infant; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000706:statistics & numerical data; D012680:Sensitivity and Specificity; D013019:South Africa / Q000453:epidemiology
chemical_list: D017931:DNA Primers; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines