[Studies on the status of immune memory after completion of hepatitis B vaccination].
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
Li
Yan-ping
YP
Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention, Nanning 530021, China.
Li
Rong-cheng
RC
Fang
Kong-xiong
KX
Li
He-min
HM
Hu
Zhong-yu
ZY
He
Peng
P
Wu
Xiao-yin
XY
Zhang
Rui
R
Liang
Zheng-lun
ZL
Zhuang
Hui
H
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
D017325:Hepatitis B Vaccines; D007376:Interleukin-2