title: Response to booster doses of hepatitis B vaccine among young adults who had received neonatal vaccination.
abstract: BACKGROUND
  Newborns who have received hepatitis B immunization in 1980s are now young adults joining healthcare disciplines. The need for booster, pre- and post-booster checks becomes a practical question.
  
  
  OBJECTIVE
  The aim of this study is to refine the HBV vaccination policy for newly admitted students in the future.
  
  
  METHODS
  A prospective study on medical and nursing school entrants to evaluate hepatitis B serostatus and the response to booster doses among young adults.
  
  
  RESULTS
  Among 212 students, 17-23-year-old, born after adoption of neonatal immunization, 2 (0.9%) were HBsAg positive, 40 (18.9%) were anti-HBs positive. At 1 month after a single-dose booster for anti-HBs-negative students, 14.5% had anti-HBs <10 mIU/mL, 29.0% and 56.5% were 10-100 and >100 mIU/mL, respectively. The anti-HBs levels were significantly higher for females than males (mean [SD]: 431 [418] vs. 246 [339] mIU/mL, P = 0.047). At 2-4 month after the third booster dose, 97.1% had anti-HBs >100 mIU/mL and 2.9% had 10-100 mIU/mL.
  
  
  CONCLUSIONS
  Pre-booster check is still worthwhile to identify carriers among newly recruited healthcare workers born after adoption of neonatal immunization. A 3-dose booster, rather than a single dose, is required for the majority to achieve an anti-HBs level >100 mIU/mL, as memory immunity has declined in a substantial proportion of individuals. Cost-effectiveness of post-booster check for anti-HBs is low and should be further evaluated based on contextual specific utilization of results.
authors.affiliation: Department of Microbiology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China.
authors.forename: Paul K S
authors.initials: PK
authors.lastname: Chan
authors.affiliation: Department of Microbiology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China.
authors.forename: Karry L K
authors.initials: KL
authors.lastname: Ngai
authors.affiliation: Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China.
authors.forename: Terence T
authors.initials: TT
authors.lastname: Lao
authors.affiliation: School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China.
authors.forename: Martin C S
authors.initials: MC
authors.lastname: Wong
authors.affiliation: Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China.
authors.forename: Theresa
authors.initials: T
authors.lastname: Cheung
authors.affiliation: Department of Microbiology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China.
authors.forename: Apple C M
authors.initials: AC
authors.lastname: Yeung
authors.affiliation: Department of Microbiology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China.
authors.forename: Martin C W
authors.initials: MC
authors.lastname: Chan
authors.affiliation: Faculty of Medicine; and University Health Service, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China.
authors.forename: Scotty W C
authors.initials: SW
authors.lastname: Luk
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006509:Hepatitis B / Q000276:immunology* / Q000517:prevention & control* / Q000821:virology; D006510:Hepatitis B Antibodies / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000276:immunology* / Q000627:therapeutic use; D006515:Hepatitis B virus / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D007117:Immunization, Secondary / Q000379:methods*; D007156:Immunologic Memory / Q000276:immunology*; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies; D014611:Vaccination; D055815:Young Adult
chemical_list: D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines