Persistence of antibodies to the surface antigen of the hepatitis B virus (anti-HBs) in children subjected to the Expanded Programme on Immunization (EPI), including hepatitis-B vaccine, in Thailand.
Will hepatitis-B vaccine administered at birth, and at 2 and 6 months of age, as an integral part of Thailand's Expanded Programme on Immunization, provide long-term protection? In an attempt to answer this question, residents of five provinces (representing five distinct geographical areas of Thailand) who were aged 1-10 years and had received this course of vaccination were enrolled on a serological study. Each was tested, with ELISA, for the surface antigen of hepatitis B (HBsAg) and for antibodies against this antigen (anti-HBs) or against the core antigen (anti-HBc). Over all age-groups, the prevalences of HBsAg, anti-HBs and anti-HBc were 0.67%, 71.4% and 5.5%, respectively. Although the prevalence of anti-HBs decreased with age, it remained at 56%-65% among those aged 6-10 years. Between 2% and 17% of the subjects aged 1-9 years had high titres of anti-HBs. Based on these results, an additional booster, still a controversial issue, does not appear to be required in order to prevent infection with hepatitis B virus and thus permit the eventual eradication of chronic carriage and its fatal sequelae in Thailand.
Poovorawan
Y
Y
Department of Paediatrics, Faculty of Medicine, Chulalongkorn University & Hospital, Bangkok, Thailand. yong.p@chula.ac.th
Theamboonlers
A
A
Hirsch
P
P
Vimolket
T
T
Sinlaparatsamee
S
S
Chaiear
K
K
Siraprapasiri
T
T
Khwanjaipanich
S
S
Owatanapanich
S
S
Chunsuttiwat
S
S
D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006509:Hepatitis B / Q000276:immunology* / Q000517:prevention & control; D006510:Hepatitis B Antibodies / Q000097:blood*; D006512:Hepatitis B Core Antigens / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood; D017325:Hepatitis B Vaccines / Q000276:immunology* / Q000627:therapeutic use; D006801:Humans; D017589:Immunization Programs; D007117:Immunization, Secondary; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D013785:Thailand; D016896:Treatment Outcome
D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines