Application of Real-Time PCR method for evaluation of measles vaccine heat stability

The Plaque Forming Unit[PFU] and Tissue Culture Infectious Dose50[TCID[50]] methods are used for evaluation of vaccine heat stability and effect of various stabilizers on thermal stability of vaccines. The aim of present study is using Real-Time PCRtechniquefor estimation of vaccine degradation rate and thermal stability of measles vaccines. Lyophilized measles vaccines containing three various stabilizers were reconstituted with distilled water. Three vial of each vaccine incubated at25 degree C for 0, 4 and 8 hours. Titer of virus in vaccines calculated by TCID[50] method. Also after RNA Extraction and cDNA synthesis, the RNA copy numbers of viruses in vaccines were estimated by absolute quantitative Real-Time PCRtesting. The data were analyzedby SPSS 19 and Sigma Plot 11 software.The result of this study showed there is a significant relationshipbetween vaccine degradation rate calculated with TCID[50] and Real-Time PCR method [p<0.05]. ThereforeReal-Time PCR is a good complement or appropriate replacement to traditional methods.Titration methods based on cell culture are gold tests for titration of viral vaccines and estimation of heat stability but Real-Time PCR technique can also be used for this goals. This method is faster, cheaper and easier than TCID[50]

Increased the specificity and sensitivity of monospecific antibody against host cell protein [HCP] in quality control of hepatitis B recombinant vaccine

One of the most important aspects in recombinant biologic production, based on GMP rules, is the accuracy of final product quality control, especially assessment of host cell macromolecules contamination rate in final product. The purification requirement can be eliminated when the yeast cell containing the recombinant protein is used as a host cell. It is possibile that the final product contaminated to the host cell protein during purification stages of HBsAg [HBV vaccine]. The protein purification costs depend on the purification procedures required. Nowadays several companies produce commercial kits for identification and assessment of host cell protein contamination based on ELISA and Western blotting methods. But high prices, difference in sensitivity and lack of easy access to these kits sometimes create problems. So, in this study, two methods of Ammonium sulphate and caprilic acid precipitation technique were used separately for IgG purification. The results showed that IgG purification increased by 97% in caprylic acid method, compared with only a 77% increase in ammonium sulphate method. There were also significant differences in specificity and sensitivity between our standardized ELISA technique and using commercial kit [Cygnus CHO HCP]