标题: China:Antibody levels and immune memory 23 years after hepatitis B vaccination [打印本页] 作者: StephenW 时间: 2011-2-8 14:55 标题: China:Antibody levels and immune memory 23 years after hepatitis B vaccination
本帖最后由 风雨不动 于 2012-4-14 15:39 编辑
Vaccine. 2011 Jan 27. [Epub ahead of print]
Antibody levels and immune memory 23 years after primary plasma-derived
hepatitis B vaccination: Results of a randomized placebo-controlled trial cohort
from China where endemicity is high.
Wu Q, Zhuang GH, Wang XL, Wang LR, Li N, Zhang M.
Department of Epidemiology and Biostatistics, Xi'an Jiaotong University College
of Medicine, Xi'an, Shaanxi 710061, PR China.
Abstract
The duration of protection of hepatitis B vaccine remains incompletely
understood. To assess the long-term protection provided by a primary vaccine
series, the current study again recruited all subjects of a previous randomized
placebo-controlled trial cohort 23 years after vaccination. Two hundred and
sixty-one healthy children aged 5-9 years living in a highly HBV-endemic country
were enrolled in the primary trial and received three doses of plasma-derived
vaccine or placebo. The primary placebo receivers who did not receive any
immunization against hepatitis B were used as non-vaccinated controls in the
current study. After eliminating the interference of an early booster dose and
vaccines outside the study, 48.1% (39/81) vaccinees still maintained anti-HBs
titers ≥10mIU/mL at Year 23, higher than 34.7% (26/75) in non-vaccinated
controls (P=0.088). 75-100% of vaccinees with anti-HBs titer <10mIU/mL at Year
23 in different sub-groups divided according to early immune backgrounds
developed a rapid and robust antibody anamnestic response after a booster dose,
highly significantly different from non-vaccinated controls who received the
same dose of vaccine (7.5%, P<0.01). No case of clinically significant HBV
infection was found in the primary cohort during the whole 23 years, but 10
transient HBsAg seroconversions in the primary placebo group and one in the
primary vaccine group were determined. Anti-HBc positive rate obviously tended
to be lower in vaccinees compared with non-vaccinated controls at Year 23. These
results suggest a persisting immune memory and certain protection for 23 years
after primary vaccination in children living in highly HBV-endemic areas.
Clinically insignificant infections, which cannot be avoided and may often occur
in vaccinees, play a positive role in the maintaining of immunity to HBV.
Booster doses should be unnecessary for more than 20 years after a full primary
immunization in children (as catch-up vaccination) and, also likely, in newborns
living in highly HBV-endemic areas.