Transmission of "a" determinant variants of hepatitis B virus in immunized babies born to HBsAg carrier mothers.
Hepatitis B virus (HBV) surface antigen mutations may lead to immune escape and eventually cause failure of immunization. In this report, we identified immune escape variants in immunized babies born to hepatitis B surface antigen (HBsAg) carrier mothers. A total of 68 babies were followed up for 2 years after the full course of vaccination; 2.9% (2/68) of babies were found to be infected with the variant HBV in spite of preexisting antibody to surface antigen (anti-HBs) at 24 months post immunization. Both infants were positive for HBV-DNA; sequencing results of the "a" determinant region of the surface gene revealed that both babies had point mutations at a different nucleotide position resulting in various amino acid substitutions. In addition, an intriguing variant having an addition-deletion mutation was observed in one of the babies. This is the first report to show the addition-deletion variant of HBV in India. However, the immunological significance of the above HBV variants needs to be further elucidated.
Velu
Vijayakumar
V
Department of Medical Microbiology, Dr ALM Post Graduate Institute of Basic Medical Sciences and National Referral Centre for Viral Hepatitis, University of Madras, Chennai, India. vvjai2000@yahoo.com
Saravanan
Shanmugam
S
Nandakumar
Subhadra
S
Dhevahi
Elumalei
E
Shankar
Esaki Muthu
EM
Murugavel
Kailapuri Gangatharan
KG
Kumarasamy
Thangaraj
T
Thyagarajan
Sadras Panchatcharam
SP
D000595:Amino Acid Sequence; D006509:Hepatitis B / Q000276:immunology* / Q000635:transmission* / Q000821:virology; D006510:Hepatitis B Antibodies / Q000097:blood / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000097:blood / Q000235:genetics*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006515:Hepatitis B virus / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D018445:Infectious Disease Transmission, Vertical; D008969:Molecular Sequence Data; D009035:Mothers; D009154:Mutation; D016415:Sequence Alignment
D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines