title: [Studies on the status of immune memory after completion of hepatitis B vaccination].
abstract: OBJECTIVE
  To study the immune memory in vaccinees after the completion of a full schedule hepatitis B immunization.
  
  
  METHODS
  One thousand and two hundred one infants born in 1987 -1989 were immunized with 3 doses of plasma derived hepatitis B vaccine, while 2484 newborn babies during 1996-1999 were injected with 3 doses of the yeast recombinant hepatitis B vaccine. All of the infants under observation were tested for HBsAg, anti-HBs and anti-HBc, in 2005. Of 959 individuals negative for anti-HBs (< 10 mIU/ml), HBsAg and anti-HBc, 228 were immunized with plasma-derived vaccine and 731 with yeast recombinant vaccine after birth. All of them were detected for anti-HBs 15 days after a booster of 10 Ipg yeast recombinant vaccine. In addition, interleukin-2 (IL-2) was detected in 11 non-responders and 22 responders after boostering, using an enzyme-linked immunospot (ELISPOT). The anti-HBs levels of 190 individuals (91 with plasma derived vaccine and 99 with yeast recombinant vaccine) who had had quantitative data on their antibody status after the primary hepatitis B vaccination, were compared with that after the boostering.
  
  
  RESULTS
  Among the individuals who received plasma derived vaccine 16-18 years ago, 79.82% of them showed the signs of immune memory after one booster, with a geometric mean titer (GMT)of 325.69 mIU/ml. Of the individuals who received the yeast recombinant vaccine 6-9 years ago, 95.62% showed immune memory after one booster,with its GMT of 745.18 mIU/ml. Anti-HBs levels induced by the booster were associated with that after the primary immunization. The positive rate of IL-2 was 40.91% in subjects with good immune memory. However, IL-2 was not detected in non-responders after the booster (P < 0.01).
  
  
  CONCLUSIONS
  Most of the individuals who had received a completed schedule of primary hepatitis B vaccination and seroconverted from anti-HBs positive to negative,showed the signs of having immune memory after the booster. Only a small proportion of the vaccinees had lost their immune memory during the long term follow-up period, suggesting that these individuals should receive a booster of hepatitis B vaccine in the highly endemic areas of hepatitis B. Hepatitis B virus; Immune memory; Booster immunization
authors.affiliation: Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention, Nanning 530021, China.
authors.forename: Yan-ping
authors.initials: YP
authors.lastname: Li
authors.forename: Rong-cheng
authors.initials: RC
authors.lastname: Li
authors.forename: Kong-xiong
authors.initials: KX
authors.lastname: Fang
authors.forename: He-min
authors.initials: HM
authors.lastname: Li
authors.forename: Zhong-yu
authors.initials: ZY
authors.lastname: Hu
authors.forename: Peng
authors.initials: P
authors.lastname: He
authors.forename: Xiao-yin
authors.initials: XY
authors.lastname: Wu
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Zheng-lun
authors.initials: ZL
authors.lastname: Liang
authors.forename: Hui
authors.initials: H
authors.lastname: Zhuang
mesh_terms: D000917:Antibody Formation; D006509:Hepatitis B / Q000276:immunology / Q000517:prevention & control*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007156:Immunologic Memory; D007223:Infant; D007231:Infant, Newborn; D007376:Interleukin-2 / Q000097:blood
chemical_list: D017325:Hepatitis B Vaccines; D007376:Interleukin-2