Stable seroepidemiology of hepatitis B after universal immunization in Taiwan: A 3-year study of national surveillance of primary school students.
BACKGROUND
This study is aimed to investigate if there was increased risk of HBV acquisition among first graders in Taiwan during a 3-year follow-up period.


METHODS
A total of 1545 healthy first graders, who were vaccinated against HBV in infancy, were recruited in 2005. All subjects were checked for hepatitis B surface antigens (HBsAg), antibodies to HBsAg (anti-HBs), and to the hepatitis B core antigen (anti-HBc). Nucleotide sequence of the "a" determinant of HBsAg was determined by polymerase chain reaction and direct sequencing in the HBsAg carriers.


RESULTS
Among 1545 subjects, 0.78% were HBsAg seropositive, 54.30% were anti-HBs seropositive, and 1.68% anti-HBc seropositive. Three of the 10 HBV carriers (30%), whose HBV DNA were sequenced for the S gene, had surface antigen mutants at the "a" determinant.


CONCLUSIONS
There were no new chronic HBV infections in this cohort of children for two consecutive years. HBV S gene vaccine escape mutants did exist in the vaccine-failure population, but they may not have made a major health impact.
Chen
Ching-Yi
CY
Department of Pediatrics, College of Medicine and Children's Hospital, National Taiwan University, Taipei 100, Taiwan.
Hsu
Hong-Yuan
HY
Liu
Cheng-Chuan
CC
Chang
Mei-Hwei
MH
Ni
Yen-Hsuan
YH
D002353:Carrier State / Q000453:epidemiology; D002648:Child; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology* / Q000235:genetics; D006510:Hepatitis B Antibodies / Q000097:blood; D006512:Hepatitis B Core Antigens / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood; D017325:Hepatitis B Vaccines / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D016036:Seroepidemiologic Studies; D013624:Taiwan / Q000453:epidemiology
D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines