Unusual hepatitis B surface antigen variation in a child immunised againsthepatitis B

Perinatal transmission of and infection with hepatitis B (HBV) in early chi ldhood are observed in a small proportion of the offspring of hepatitis B s urface antigen (HBsAg)-positive mothers who are vaccinated against HBV imme diately after giving birth. The children may be infected by wild-type HBV o r by variants with amino acid substitutions in the "a" determinant of HBsAg , particularly at position 145 and, rarely, at positions 120, 126, 129, 131 , 141, and 144. Four hundred and forty-six newborn infants of HBsAg-positiv e mothers in the northeastern part of the Czech Republic received combined active and passive immunisation against HBV. Only one child became an HBsAg carrier. This followed a mild, acute HBV illness in the beginning of the s econd year of his life. HBV DNA encoding the "a" determinant and surroundin g region of HBsAg was sequenced after amplification from the plasma of the child and his mother. The child was infected with variants of HBsAg with su bstitutions at residues 137 and 139. The virus of the mother had changes at residues 120 and 121. HBV from both child and mother had an unusual substi tution at residue 118 and seemed to be of the ayw subdeterminant. J. Med. V irol. 67:11-14, 2000. (C) 2000 Wiley-Liss, Inc.