摘要
ＡｂｓｔｒａｃｔＡＩＭＴｏｉｄｅｎｔｉｆｙｔｈｅｐｅｒｓｉｓｔｅｎｃｅｏｆｉｍｍｕｎｅｐｒｏｔｅｃｔｉｏｎｏｆＣｈｉｎａｍａｄｅ，ｐｌａｓｍａｄｅｒｉｖｅｄｈｅｐａｔｉｔｉｓＢｖａｃｃｉｎｅａｆｔｅｒｉｎｆａｎｃｙｉｍｍｕｎｉｚａｔｉｏｎａｎｄｔ...
AIM To identify the persistence of immune protection of China made, plasma derived hepatitis B vaccine after infancy immunization and the time table of booster immunization. METHODS A cross sectional follow up study and an experimental study on booster were used for the evaluation of the serological effect 7 years after vaccination and the antibody anamnestic response. Radioimmunoassay was used for the detection of hepatitis B virus markers. RESULTS The protective anti HBs positive rates of 1018 children, who were vaccinated according to the regimen of three doses of 10μg hepatitis B vaccine in their infancy, declined from 75 0% during the first two years to 48 2% in the 7th year after the first dosage, however, the positive rates for HBsAg and anti HBc always fluctuated at a low frequency. A total of 144 subjects aged 6 or 7 years, who were negative for both HBsAg and anti HBc before booster, were selected from 1018 children of the follow up study, and boosted with 1μg intradermally or 2μg hypodermically hepatitis B vaccines. Their anti HBs GMT and anti HBs positive rates were 190 6mIU/ml and 89 6% in the first month after booster, significantly higher than 14 7mIU/ml and 54 9% before booster ( P <0 01), and declined back to 25 3mIU/ml and 75 5% in the 12th month; among 65 children with the anti HBs negative before booster, 40 had a level of anti HBS≥ 100mIU/ml one month after booster, suggesting retention of immune memory in most of them. CONCLUSION No need for revaccination against hepatitis B in the 7th year after the initial immunization due to better persistence of immune protection of the vaccine and retention of immune memory to hepatitis B virus in the vast majority of the vaccinees.
