Current aspects of hepatitis B surface antigen mutants in Singapore

• Published in: Journal of viral hepatitis Vol. 5; no. s2; pp. 17 - 23
• Main Authors: Oon, C. -J., Chen, W. N.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.11.1998
• Subjects: Adolescent; antigenicity; Carrier State; Child; Epitopes - genetics; HBsAg; HBV; Hepatitis B - prevention & control; Hepatitis B - transmission; Hepatitis B - virology; Hepatitis B Antibodies - biosynthesis; Hepatitis B Antibodies - immunology; Hepatitis B Surface Antigens - genetics; Hepatitis B Surface Antigens - immunology; Hepatitis B Vaccines - immunology; Hepatitis B virus; Hepatitis B virus - genetics; Hepatitis B virus - immunology; hepatocellular carcinoma; Humans; Infectious Disease Transmission, Vertical; Mutation; Singapore - epidemiology; stability; transmission; vaccine-escape mutants; Singapore
• ISSN: 1352-0504; 1365-2893
• DOI: 10.1046/j.1365-2893.1998.0050s2017.x

Mutations occurring on the major antigenic ‘a’ determinant of hepatitis B surface antigen (HBsAg) have been detected in immunized Singapore children, despite immunoprophylaxis with hepatitis B immune globulin and HBV vaccine. These vaccine‐escape HBsAg mutants display a predominance of the Gly145‐to‐Arg145 mutation in the antigenic ‘a’ determinant. Our latest follow‐up studies indicate the stability of this as well as other vaccine‐escape HBsAg mutants over time. We have also identified HBsAg mutants in immunized children with amino acid substitutions outside the ‘a’ determinant. Transmission of various vaccine‐escape HBsAg mutants have been shown in our epidemiological studies. Detection of HBsAg mutants, carrying amino acid changes at various position of the ‘a’ determinant in random population, points to their emergence in Singapore before the implementation of the vaccination programme. Of significant interest is the recent identification of vaccine‐escape HBsAg mutants in hepatocellular carcinoma.