ABSTRACT
@#Objective To develop and verify a qPCR method for the qualitative and quantitative analysis of residual host DNA in human rabies vaccine(Vero cells) stock solution.Methods The qPCR standard curve was established by using the Vero cell DNA quantitative national standard,and the residual host DNA was extracted using magnetic beads.The specificity,repeatability,intermediate precision,accuracy and durability of the method were verified,and the linear range and limit of quantification were determined.The residual DNA of three batches of human rabies vaccine(Vero cells) stock solution was quantitatively analyzed and the fragment size was qualitatively analyzed by using this method.Results The correlation coefficients(R~2) of Vero cell DNA quantitative national standard amplification standard curve were all more than 0.99 by qPCR,and the quantitative range was 0.3 pg/mL～30 ng/mL.The method showed good specificity and repeatability.In the verification of intermediate precision,accuracy and durability,the relative standard deviations(RSD)of detection results of the samples were all less than 10%.The residual DNA content of Vero cells in three batches of stock solution was 0.20～0.77 ng/dose,which met the relevant standard of Chinese Pharmacopoeia(Volume Ⅲ,2020edition).The residual DNA fragments greater than 154 bp accounted for 52%～63%.Conclusion The developed qPCR method for the detection of residual DNA in human rabies vaccine(Vero cells) stock solution had good specificity,repeatability,intermediate precision and durability,and qualitatively and quantitatively analyzed the residual DNA rapidly and accurately,which was of great significance for improving the detection and control of residual DNA content in the production process and final product of human rabies vaccine(Vero cells).
ABSTRACT
Objective:To investigate the effects of different production processes on sensitization responses to human diploid cell rabies vaccines.Methods:This study randomly collected 360 serum samples in clinical trials of four rabies vaccines with different production processes. Total IgE levels at different time points were detected by ELISA. SPSS19.0 software was used for statistical analysis.Results:Total IgE test results showed that the seropositive rate was 20% (6/30) for all four vaccines. The lowest mean value of total IgE was 9 IU/ml and the highest was 210 IU/ml. Repeated measures analysis of variance showed that there was no significant difference in total IgE levels at different sampling time points ( P=0.284), and the total IgE level in people injected with multistep concentrated human diploid cell rabies vaccine was significantly below that in people immunized with Vero cell rabies vaccine ( P=0.024). Conclusions:Increasing the immune dosage of human rabies vaccine could not result in a rise in total IgE. Human diploid cell rabies vaccines had good safety as the production process could remove most of allergenic impurities.
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This article referred to the relevant guidelines for vaccine clinical trials and the accumulated experience in the development and review of human rabies vaccines, as well as combined the technical recommendations for human rabies vaccines from major health facilities such as WHO, to discuss the key considerations in the design of clinical trials for human rabies vaccines, including control vaccines, evaluation of efficacy endpoints, clinical subjects, the sample size, immunity persistence, re-exposure immunization schedule and post-marketing study. This article aimed to provide reference for the design of human rabies vaccine clinical trials.
ABSTRACT
A simple method was established for the determination of β-propiolactone (BPL) in human inactivated rabies vaccine by gas chromatography-mass spectrometry (GC-MS). The determination was performed on an Agilent HP-INNOWAX (30m × 0.32mm i.d., 0.25 μm) capillary column at the temperature of 80 °C. Electrospray ionization (ESI) was used by selective ion detection at m/z 42. The temperature for ESI source and inlet was set at 230 °C and 200 °C, respectively. Helium was used as the carrier gas at a flow rate of 25.1 mL/min. The total run time was 8 min. Acetonitrile and other components in the sample did not interfere with the determination of BPL. The results showed good linearity of BPL in the range of 0.50–10.01 μg/mL, with the limit of detection and the limit of quantification of 0.015 μg/mL and 0.050 μg/mL, respectively. Satisfactory precision was achieved for the current developed method. The method was applied to detect 6 batches of vaccine samples, and the results indicated that the target analyte BPL was present in three batches of unpurified samples, but was not detected in the purified samples, indicating the test samples were qualified. The established method was proved to be simple, versatile and sensitive, which can meet the requirements of quality control of BPL in human inactivated rabies vaccine.