Evaluation of immune persistence of vaccine / 中华预防医学杂志

The evaluation methods of immune persistence include direct evaluation, indirect evaluation, model prediction, and meta-analysis and so on. Direct evaluation is the gold standard for evaluating the immune persistence of vaccines by quantifying the protective effect of vaccines on the onset and (or) infection of preventable diseases. Indirect evaluation of immune persistence by immunological surrogate indicators is more widely used in practice. In addition, mathematical models and meta-analysis can also be used to evaluate the immune persistence of vaccines. It is of great significance to select the appropriate evaluation method to analyze the immune persistence of the vaccine according to the specific situation.

Immunization with HBsAg-Fc fusion protein induces a predominant production of Th1 cytokines and reduces HBsAg level in transgenic mice / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The Fc receptor associated pathway might improve the immune responses against hepatitis B virus (HBV) as previously described by us. In addition, the Flt3 ligand (FL) has been reported to potentiate antigen presenting cells in vivo and may act as a potential adjuvant to boost antigen-specific immune responses. In this study, the immune efficacies of a set of fusion proteins of HBsAg and Fc and/or FL were evaluated in HBsAg transgenic mice.</p><p><b>METHODS</b>The fusion proteins composed of HBsAg and the Fc domain of murine IgG1 (HBsAg-Fc) and/or the Flt3 ligand, and yeast-derived recombinant HBsAg were used as immunogen to immunize HBsAg transgenic mice, respectively. Serum and liver HBsAg levels, serum anti-HBsAg and cytokine profile, and the activities of alanine aminotransferase (ALT)/AST were investigated after immunization.</p><p><b>RESULTS</b>After six injections, the most pronounced decrease in serum and liver HBsAg levels was observed in the HBsAg-Fc immunized group. In addition, serum Th1 cytokines and ALT/AST activities were highest in this group, indicating an effective induction of a favorable cellular immune response. Interestingly, the fusion protein containing HBsAg-Fc and the Flt3 ligand stimulated an alternative Th1-type immune response featured with high level productions of tumor necrosis factor α (TNF-α) and monocyte chemoabstractant protein 1 (MCP-1), causing a more severe cytotoxicity in hepatocytes while showed less effective in reducing serum HBsAg level.</p><p><b>CONCLUSION</b>HBsAg-Fc is effective in eliciting both the humoral and cellular immune responses against HBsAg in HBsAg transgenic mice, which makes it a potential immunogen for the immunotherapy of chronic hepatitis B.</p>

Valuation on the immunization efficacy on the 23 years who had received plasma-derived HBV vaccine as newborns / 中华流行病学杂志

<p><b>OBJECTIVE</b>To observe the long-term effect of plasma-derived HBV vaccine.</p><p><b>METHODS</b>The effect of a plasma-derived HBV vaccine which was given to children born in 1986 in Huangpu district in Shanghai were followed up once every two years and testing for HBsAg, anti-HBs and anti-HBc was carried out. Compared to background results from cross-sectional survey of hepatitis B virus in 1984 and 1985 (as internal control) as well as finding of survey targeted in non-plasma-derived HBV vaccine of children born in the same time in the nearby area from results investigated in 1991 (as external control), positive rate was calculated to assess the effect of protection.</p><p><b>RESULTS</b>The population immunized was followed up for 23 years and 5993 blood samples were collected. During the period of follow-up, the positive rate of anti-HBs decreased from 89.01% to 18.77% and the average level was 40.39%. The average positive rate of anti-HBc was 1.87%. The annual positive rate fluctuated around the average level. HBsAg positive rate remained less than 1.00% (0.46% - 0.98%), with an average of 0.62% (37/5993). Ranges of positive efficacy were from 81.37% to 95.78% against background control and 72.76% against external control.</p><p><b>CONCLUSION</b>The plasma-derived HBV vaccine showed a good long-term protective effect and there was no need for boosting the immunization 23 years later.</p>

Evaluation on the immunization efficacy on the 23 years who had received plasma-derived HBV vaccine as newborns / 中华流行病学杂志

Objective To observe the long-term effect of plasma-derived HBV vaccine.Methods The effect of a plasma-derived HBV vaccine which was given to children born in 1986 in Huangpu district in Shanghai were followed up once every two years and testing for HBsAg,anti-HBs and anti-HBc was carried out.Compared to background results from cross-sectional survey of hepatitis B virus in 1984 and 1985 (as internal control) as well as finding of survey targeted in non-plasma-derived HBV vaccine of children born in the same time in the nearby area from results investigated in 1991 (as external control),positive rate was calculated to assess the effect of protection.Results The population immunized was followed up for 23 years and 5993 blood samples were collected.During the period of follow-up,the positive rate of anti-HBs decreased from 89.01％ to 18.77％ and the average level was 40.39％.The average positive rate of anti-HBc was 1.87％.The annual positive rate fluctuated around the average level.HBsAg positive rate remained less than 1.00％ (0.46％-0.98％),with an average of 0.62％ (37/5993).Ranges of positive efficacy were from 81.37％ to 95.78％ against background control and 72.76％ against external control.Conclusion The plasma-derived HBV vaccine showed a good long-term protective effect and there was no need for boosting the immunization 23 years later.

Evaluation on the immunization efficacy on the 23 years who had received plasma-derived HBV vaccine as newborns / 中华流行病学杂志

Objective To observe the long-term effect of plasma-derived HBV vaccine.Methods The effect of a plasma-derived HBV vaccine which was given to children born in 1986 in Huangpu district in Shanghai were followed up once every two years and testing for HBsAg,anti-HBs and anti-HBc was carried out.Compared to background results from cross-sectional survey of hepatitis B virus in 1984 and 1985 (as internal control) as well as finding of survey targeted in non-plasma-derived HBV vaccine of children born in the same time in the nearby area from results investigated in 1991 (as external control),positive rate was calculated to assess the effect of protection.Results The population immunized was followed up for 23 years and 5993 blood samples were collected.During the period of follow-up,the positive rate of anti-HBs decreased from 89.01％ to 18.77％ and the average level was 40.39％.The average positive rate of anti-HBc was 1.87％.The annual positive rate fluctuated around the average level.HBsAg positive rate remained less than 1.00％ (0.46％-0.98％),with an average of 0.62％ (37/5993).Ranges of positive efficacy were from 81.37％ to 95.78％ against background control and 72.76％ against external control.Conclusion The plasma-derived HBV vaccine showed a good long-term protective effect and there was no need for boosting the immunization 23 years later.

The immunological effects of three doses of a live attenuated hepatitis A vaccine (H2 strain) in 8 years / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To observe the immunological effects of three doses of H2 strain live attenuated hepatitis A vaccine 8 years after the administration and to compare with that of one dose of the vaccine.</p><p><b>METHODS</b>In a country area, 110 children of 1 to 7 years old susceptible to HAV were screened and administered with one dose of the vaccine, as group B; Group A were 42 children from one of the villages and administered with 3 doses of the vaccine according to 0, 2, 6 month schedule. Blood samples were taken for the children 1, 2, 6, 7, 8, 12, 24, 36 and 96 months after the administrations respectively and detected for anti-HAV antibody.</p><p><b>RESULTS</b>For group B, the sero conversion rate of anti-HAV and GMC reached peak at 92.2% and 126.2 mIU/ml respectively, and then, began to drop with time; For group A, after 2 dose of the vaccine, the sero-conversion rate reached 100%, and the GMC reached peak of 2 739 mIU/ml one month after the third dose at 7 months. So that, group A has a better short-term immunological effects than that of group B. During 36 through 96 months, the anti-HAV positive rate in group B was 75%-71% and 80-89 mIU/ml respectively, and comparatively in group A were 100% and 918.2-480.6 mIU/ml respectively. The differences between group A and B were significantly important.</p><p><b>CONCLUSION</b>A 3-dose schedule administration of H2 strain live attenuated hepatitis A vaccine has better immunological effects than 1-dose schedule in 8years and further observations are needed.</p>

An effective method to reduce bias between two compared groups: propensity score / 中华流行病学杂志

<p><b>OBJECTIVE</b>Through introduction of principal theory and algorithm of propensity score to design SAS macro programs for binary data.</p><p><b>METHODS</b>Propensity score method was used to compare the differences of character variables between two groups, and the association of DNR (Do Not Resuscitate) with the mortality of congestive heart failure was evaluated with different methods.</p><p><b>RESULTS</b>Significant differences among the character variables between two groups were effectively balanced with stratification or matching method. The odds ratios of DNR with the in-hospital mortality rate of congestive heart failure were estimated identical with different algorithms and to find that the association of DNR to in-hospital mortality was highly significant.</p><p><b>CONCLUSION</b>Propensity score was a good algorithm that could be used to analyze any kind of observational data for matching the effects among the character variables.</p>

Studies on Mutagenesis of Virginiamycin Producing Strain X-435 / 微生物学通报

Streptomyces sp.X-435 isolated from a soil sample collected in the suburbs of Beijing was proved to be a produce Virginiamycin.To improve the productivity of the Virginiamycin of Streptomyces sp.X-435,the spores of strain X-435 were treated with UV.The three types of colony,strawhat,wrinkled,blad,were isolated on Gaose's medium plates after mutation.Among them,the colonies of strawhat type exhibited positive mutation and were picked up as objects of screening.After five generation of mutation,the mutant F5-25-u-28 was selected which potency of Virginiamycin was about 20times higher than that of the beginning strain by flask fermentation and was also genetic stable.