ABSTRACT
Objective To evaluate the long-term immunogencity and effectiveness of live attenuated hepatitis A (HA) vaccine (H2 strain) after one dose injection, through a 15 years' follow up observation. Methods A total of 220 children with negative anti-HAV antibody (aged 1-3 y)were involved and followed up in Jiaojiang district, Taizhou city, Zhejiang province. Indicators would include seroconversion and geometric meantiter(GMT) levels after inoculation the vaccine with single dose at 2 m, 12 m, 6 years, 10 years and 15 years. Epidemiological observation was carried out within the 15 years to evaluate the relationship between vaccine coverage, the incidence of HA and the overall effectiveness. In the studied population, serum was tested by ELISA(calibrated by WHO international reference) and ABBOTT Axsym HAVAB mEIA. Results Seroconversion rates were found to be 98.6% and 81.3% after 2 months and 15 years of inoculation and slowly decreased. GMT level was 128 mIU/ml after 15 years, significantly higher than the required protective level of 20 mIU/ml,recommended by WHO experts. Effectiveness through the 15-year follow up program showed a significant correlation between vaccine coverage and incidence of HA in 1-15 years aged group (Kendall-Rank test, t =-0.931, P＜0.01). There was no HA case seen among the observed accumulated 236 413 person-year vaccines, compared to 4 HA cases discovered in the 27 206 personyear of the non-vaccinees. The overall protective rate reached 100%. Through a mass vaccination program on children, the whole population established an immune-defence to enable the incidence of HA decreased by 96.7%. Conclusion The long-term immunogencity and effectiveness of live attenuated hepatitis A vaccine (H2 strain) after one dose injection could last as long as 15 years.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the RT-PCR-ELISA method applied for testing live attenuated hepatitis A vaccine titer.</p><p><b>METHODS</b>A solid phase hybridization-enzyme colorimetric detection method was used for detecting specific nucleic acid. Primer labeled with biotin was used to amplify viral gene fragment, then the product was quickly hybridized with the specific probe covalently coupled on DNA-binding microplate wells. Finally, peroxidase-labeled streptavidin was used in colorimetric detection. The results were judged by reading A value. Eleven batches of live attenuated hepatitis A vaccine titer were tested by this method. The results were compared with that of routine cell culture method (CCID50).</p><p><b>RESULTS</b>The sensitivity was similar to routine cell culture method (P>0.05). This method was convenient, fast and specific.</p><p><b>CONCLUSION</b>CCID50 method may be replaced by the RT-PCR-ELISA method in evaluating the titer of live attenuated hepatitis A vaccine.</p>
Subject(s)
Base Sequence , DNA, Viral , Enzyme-Linked Immunosorbent Assay , Genes, Viral , Hepatitis A Vaccines , Hepatitis A virus , Genetics , Quality Control , Reverse Transcriptase Polymerase Chain Reaction , Sensitivity and Specificity , Vaccines, AttenuatedABSTRACT
0.05).Conclusions ATP-TCA could be used to individualize chemotherapy by selecting agents for particular patients of cervical cancer.The expression of GST-? and TS protein might be useful biomarkers to predict the resistance to DDP and 5-FU in patients with cervical cancer.