ABSTRACT
Objective To understand the changes of hepatitis B infection rates,before and after the hepatitis B vaccine Was included into EPI.and to evaluate the effect of immunization which would lead to the development of a more appropriate hepatitis B control strategy.Methods Seroepidemiologic method,with multi-section random sampling method were chosen.14 sites from 8 counties were involved.2-4 ml of the vein blood was drawn from all the individuals engaged in the study including 3806 samples.HBsAg,anti-HBs.anti-Hbe of the samples were tested with ELISA.Results Standardized positive rates of HBsAg and HBsAb were found as 7.05%and 29.77%respectively with the overall infection rate of HBV as 40.30%.The hepatitis B vaccine coverage of the children under 15 years was 70.73%and the positive rates for both HBsAg and anti-HBS were 2.62%and 56.68%.respectively.The coverage of hepatitis B vaccine among children under 3 years was 83.44%and the positive rates of both HBsAg and anti-HBs were 1.47%and 67.69%respectively.hepatitis B vaccine coverage of children under 3 years was 85.77%.with positive rates of HBsAg and anti-HBs as 1.78%and 75.44%respectively.Conclusion Results from our study revealed that since the introduction of hepatitis B vaccination,the prevalence rates of HBsAg and HBV infeetion had an obvious decline,especially in children aged under 15 years of old,suggesting that some changes had occurred in the epidemic characteristics ofhepatitis B in Sichuan.
ABSTRACT
<p><b>OBJECTIVE</b>To assess the feasibility of the 10 microg recombination yeast hepatitis B vaccine in the expanded applicable population group aged 5 - 18.</p><p><b>METHODS</b>People with both HBsAg and anti-HBs negative were selected to take two-stage clinical experiment and the safety and immunogenicity were observed. Safety observation was conducted in 925 subjects, while 568 for immunogenicity. The observation group (aged 5 - 18) included 493 subjects, and (age > 18) 75 enrolled in control group. For the observation group, there were three sub-groups including a child group (141, aged 5 - 6), early youth group (177, aged 12 - 13), and youth group (175, aged 16 - 18). Both groups were administered with 10 microg recombination yeast hepatitis B vaccines with 3 doses at 0 month, 1st month, 6th month. To assess the immunogenicity, the vaccination reactions were observed during the following 4 weeks in order to assess the vaccine safety. The blood samples were taken during 4 - 6 weeks after fully vaccinated, and then anti-HBs were tested with RIA and analyzed by comparing the positive rate of anti-HBs, the geometric mean titer (GMT) and the protective rate between the two groups.</p><p><b>RESULTS</b>Both observation and control group didn't show any general reactions, adverse events following immunization (AEFI) or coincidental cases when observed at 0.5 h, 6 h, 24 h, 48 h, 72 h, 1 week, 2 weeks, 3 weeks, 4 weeks after being vaccinated. The result of serum test showed, the positive rates of child group, early youth group, youth group and control group were respectively 100.00% (141/141), 97.18% (172/177), 98.29% (172/175) and 89.33% (67/75); the GMTs of anti-HBs were respectively 440.28, 875.38, 467.80, 131.06 U/L; the protective rates were respectively 100.00% (141/141), 97.18% (172/177), 97.14% (170/175) and 86.67% (65/75). The positive rate, GMT and protective rate of the experimental group were all higher than that of control group (chi(2)(positive rate) = 12.77, 5.12, 7.99; t(GMT) = 3.89, 4.13, 5.91; chi(2)(protective rate) = 16.81, 8.60, 8.44; P < 0.05).</p><p><b>CONCLUSION</b>This vaccine could be expanded to 5 - 18 year-old population with safety and effectiveness, the positive rate and protective rate of anti-HBs were both higher than that of control group.</p>