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The stability of vaccines has a major impact on the success of immunization programmes worldwide. Stability evaluation is a vital part of the assessment of the vaccine quality and safety. It should be regarded as a continuous process from the development of the vaccine through licensing to post-licensure monitoring. To ensure the quality of the vaccine, related guidelines were issued by both World Health Organization and Chinese regulatory authority. This paper reviews the progress of relevant guidelines and studies for providing the stability considerations of vaccine.
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Hepatitis virus NAT reagents are now widely used clinically. However, the qulity of domestic and foreign NAT reagents varies dramatically. The main reasons for these differences including the manufacture technique, test principle and assay procedure were discussed in this paper and current status of the quality control of the NAT reagents were also described. Finally, it was pointed out that strengthening public supervision and laboratory internal control are very important for the quality improvement of the domestic reagents.
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Objective To compare the sensitivity, specificity and consistency of five kits for quantitative detection of hepatitis B virus (HBV) DNA. Methods Four domestic fluorescence kits, A, B, C, and D, and Roche Cobas Ampliprep/Cobas TaqMan HBV test for quantitation of HBV DNA in serum, were applied to detect the National Standards, an additional plasma for sensitivity (7 times dilution), 15 plasma samples from healthy blood donor and 45 plasma samples from chronic hepatitis B patients. Results All five kits showed the correct results for the 9 positive specimens and 8 negative specimens from the National Standards. The quantitative results of specimens for sensitivity met requirements of the National Standards. The lowest concentration of HBV DNA by these three kits was 15.6 IU/mL. The lowest detection level of HBV DNA for domestic kit B was ≤500 IU/mL. There was linear correlation between the results by Roche kit and domestic kit C (r> 0.98). Kit D showed 2 false-negatives results in the 15 healthy blood donor samples. The coincidence rates between 4 domestic kits and the Roche kit ranged from 50% to 96% (A: 61%, B: 50%, C: 96%, D: 83 %). The consistency rate of kit C with the Roche kit was significantly higher than those of kit D, A and B (X2=5.62, P<0.05, X2=28. 93, P<0.01, X2=44.31,P<0.01, respectively). The consistency rates among these 5 kits were highest when testing samples with HBV DNA levels between 1×104-1×107 IU/mL. Conclusions The qualities of domestic kits vary remarkably and kit C has the greatest consistency rate with the Roche kit. Therefore, the qualities of domestic kits need to be further improved.
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Objective To evaluate anti-HEV IgG and IgM diagnostic kits with sera from convalescent hepatitis E patients and to establish the quantification method of detecting anti-HEV lgG.Methods Detect 42 convalescent serum samples of over 6 months after onset of hepatitis E patients from Jiangsu province with anti-HEV IgM and IgG diagnostic kits. Select and mix the anti-HEV IgG positive sera which were confirmed by Western blot with ORF2 and ORF3 antigen. The mixed serum was calibrated with a WHO anti-HEV Ig standard. A series quantitative linear standard was made for quantitative detection of anti-HEV IgG in hepatitis E vaccine clinical trials phase Ⅲ. Results The positive rates of the anti-HEV IgG di-agnose kits of G, K, MP, Wantai were 71.4%, 78.6%, 92.9% and 100% respectively. The positive rates of G was lower than that of MP (χ~2 = 5.19, P<0.05) and obviously lower than Wantai (χ~2 = 11.76,P<0.01). The positive rates of K was also obviously lower than that of Wantai (χ~2 =7.96, P <0.01).The positive rates of the anti-HEV IgM diagnose kits of MP, G, X, Wantai, K were 21.4%, 7.1%,21.4%, 64.3%, 78.6% respectively. The positive rate of both K and Wantai were obviously higher than that of MP(χ~2 = 15.75 ,P<0.01 ; X2 = 27.43 ,P< 0.01). With the Western blot confirmation test, 30 and 18 sera were reactive to ORF2 and ORF3 antigen separately. The anti-HEV IgG concentration of HEV-D01 mixed by 13 samples was 57.94 U/ml by the calibration. Prepare seven 1.5-fold dilution series of quantita-tive linear standard for HEV vaccine clinical trials phase Ⅲ, concentration range from 0.077 to 0.877 U/ml. The quantitive values of high, medium and low concentrations quality control samples lay in the range of average ± 2s, and the CV of quantitative values were 16%, 16%, 12% respectively. Conclusion The quality of different anti-HEY IgM and IgG diagnose kits were different. This study had set up a set of anti-HEV IgG linear quantitative standard, which fit for detecting anti-HEV IgG antibodies quantitatively in HEVvaccine clinical trial phase Ⅲ.
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Objective To prepare and study the immunogenicity of hepatitis B virus surface anti-gen (HBsAg)-tetanus toxoid (TT) conjugate vaccine. Methods Tr was activated by cyangen bromide and reacted with adipic acid dihydrazide, then HBsAg-TT conjugate was prepared by carbediimide. Conjugate, HBsAg or hepatitis B vaccine was injected subcutaneously into mice. Anti-HBsAg and HBsAg-specific T cell response elicited by these immunogens were assayed. Results New HBsAg-TT conjugate elicited higher levels of anti-HBsAg and HBsAg positive conversion rates after the immunization than did HBsAg alone or hepatitis B vaccine. Conjugate induced mesdy antibodies of the IgG2a subclass, while HBsAg alone or hepa-titis B vaccine mainly elicited anti-HBsAg in the IgG1 subclass. The number of IFN-γand IL-2 secreting T cells induced by conjugate was also significantly higher than that did by HBsAg or hepatitis B vaccine. Con-clusion This study indicated new HBsAg-TT conjugate can induce both stronger humoral and TH1 type of cellular immune response.
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<p><b>OBJECTIVE</b>To study the immunogenicity and safety of recombinant yeast-derived hepatitis B vaccine (YDV) in adults.</p><p><b>METHODS</b>One hundred and twenty-four healthy teachers aged 22 approximately 58 years with serum negative HBsAg, anti-HBs, anti-HBc and with normal temperature were randomly selected from Beipiao city, Liaoning province. All the subjects were immunized with 5 microg/0.5 ml of YDV made by Beijing Institute of Biologic Products, for three doses at an interval of one and six months, respectively.</p><p><b>RESULTS</b>The positivity of serum anti-HBs was 35.0%, 83.3%, 65.5% and 32.7% with a geometric mean titre (GMT) of 12.6 mIU/ml, 402.0 mIU/ml, 70.3 mIU/ml and 20.3 mIU/ml, respectively, three, seven, 12 and 24 months after immunization. The positivity and GMT of serum anti-HBs appeared the highest seven months after immunization, then began to decrease sharply. The positivity and GMT of serum anti-HBs in women was higher than that in men either three, or seven, or 12, or 24 months after immunization. The positivity of serum anti-HBs in those of 35 years or over was lower than that less than 35 years, seven months after immunization, but no age difference could be found 12 months after immunization. No local or systematic adverse reactions were found in all the subjects within three days after immunization.</p><p><b>CONCLUSION</b>The recombinant yeast-derived hepatitis B vaccine (YDV) is immunogenic and safe for adults, but the persistency of serum anti-HBs in after immunization should be followed-up further.</p>
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Adult , Humans , Middle Aged , Age Factors , Hepatitis B Antibodies , Blood , Hepatitis B Vaccines , Allergy and Immunology , Immunization , Sex Factors , Vaccines, Synthetic , Allergy and Immunology , Yeasts , GeneticsABSTRACT
74 primary hepatocellular carcinoma patients (PHC) and 75 controls are tested for HLA and investigated heritability. The results showed the frequency of Bw39 antigen was significantly higher in PHC patients than that in the controls. (Fisher P0.05); but the frequeney of Bw60 antigen, was lower (Fisher P0.05 ). The result of heritability proved the role ofgenetic factor in PHC development.