Chen C.-Y.HONG-YUAN HSULiu C.-C.MEI-HWEI CHANGYEN-HSUAN NI2021-01-042021-01-0420100264-410Xhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-77955056692&doi=10.1016%2fj.vaccine.2010.06.029&partnerID=40&md5=d73d3b190e859a8d4551fd34b234508bhttps://scholars.lib.ntu.edu.tw/handle/123456789/537013Background: 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. Conclusion: 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. ? 2010 Elsevier Ltd.[SDGs]SDG3hepatitis B antibody; hepatitis B core antigen; hepatitis B surface antigen; virus DNA; hepatitis B antibody; hepatitis B core antigen; hepatitis B surface antigen; hepatitis B vaccine; virus DNA; article; cohort analysis; disease surveillance; DNA sequence; female; follow up; gene; hepatitis B; Hepatitis B virus; human; human experiment; immunization; male; normal human; nucleotide sequence; polymerase chain reaction; primary school; priority journal; questionnaire; risk factor; seroepidemiology; Taiwan; virus carrier; blood; child; genetics; hepatitis B; heterozygote; Carrier State; Child; DNA, Viral; Female; Hepatitis B; Hepatitis B Antibodies; Hepatitis B Core Antigens; Hepatitis B Surface Antigens; Hepatitis B Vaccines; Humans; Male; Seroepidemiologic Studies; Taiwan; Carrier State; Child; DNA, Viral; Female; Hepatitis B; Hepatitis B Antibodies; Hepatitis B Core Antigens; Hepatitis B Surface Antigens; Hepatitis B Vaccines; Humans; Male; Seroepidemiologic Studies; Taiwanjournal article10.1016/j.vaccine.2010.06.029205984052-s2.0-77955056692