ABSTRACT
Objective To validate a cell infection-based quantitative RT-PCR for evaluating the potency of rotavirus vaccine. Methods According to the ICH ( the International Council for Harmonization) Harmonised Tripartite Guideline, the method was validated for its specificity, accuracy, precision, linearity and robustness. Results The method had good specificity as it could only amplify and detect the corre-sponding type of rotavirus strain. The recovery rates for determining the potency against rotaviruses of G2, G3 and G4 types were 97％ to 108％. The percent coefficient of variation ( CV) of both intra-plate and in-ter-plate precision was≤2. 62％, while the intraday and interday CV was≤1. 76％ and≤2. 27％, respec-tively. The CV between the two experimenters was≤7. 68％. The linearity range of the method was 4. 4-6. 5 UI for G2 type rotavirus, 3. 9-8. 3 UI for G3 type and 3. 5-8. 1 UI for G4 type. Good robustness was observed using the cells of 140 to 160 generations. Conclusions The cell infection-based quantitative RT-PCR was shown to have satisfactory specificity, accuracy, precision, linearity and robustness, suggesting that it was a suitable method for evaluating the potency of multivalent rotavirus live vaccines.
ABSTRACT
El control de calidad de las vacunas resulta fundamental para las actividades de producción, liberación lote a lote y comercialización de las vacunas. Sin embargo, en la actualidad este es un proceso que por su concepción es lento y costoso debido a que se apoya en la realización de extensas pruebas en animales para demostrar la potencia y seguridad de estos productos biológicos. El desarrollo de métodos alternativos inspirados en el principio de las 3Rs (Reducción, Refinamiento y Reemplazo) constituye una tendencia que debe impactar de manera muy significativa en la reducción de los tiempos de liberación y el costo del proceso de control de calidad de vacunas en los próximos años. En particular la sustitución de las pruebas de potencia y toxicidad in vivo por procedimientos alternativos más relevantes, rápidos, exactos, reproducibles, robustos y baratos, que incluyen la serología, la cuantificación directa de antígeno, los ensayos en cultivos celulares y el enfoque a consistencia, por solo mencionar algunos; implica un cambio de paradigma, con indiscutibles repercusiones éticas, logísticas, económicas y científico-técnicas, para el aseguramiento de los parámetros de calidad de los inmunobiológicos con el mejor balance costo-beneficio: las vacunas. Los fundamentos técnicos de estos métodos alternativos, sus ventajas y nivel de implementación a nivel internacional, así como sus principales limitaciones, son abordados en este trabajo(AU)
Vaccine quality control is crucial for the manufacturing, lot release and commercialization activities worldwide. However, the current process is by-design too slow and expensive because is based on large animal assays for assuring the potency and safety of these important biological products. The development of 3Rs alternative methods (Reduction, Refinement and Replacement) is a trend able to significantly reduce the releasing times and costs of the vaccine quality control processes in the next few years. Particularly, the replacement of the animals-based potency and toxicity assays by alternative procedures more relevant, fast, accurate, reproducible and cheap, including serology, direct antigen quantification, cell culture tests and the Consistency Approach, for just mentioning some of them, implies a paradigm shift, with undisputable ethical, logistical, economic, scientific and technical repercussions for ensuring the vaccine quality parameters. Theoretical basements, advantages and implementation levels of the alternatives methods as well as their main limitations are presented in this paper(AU)
Subject(s)
Humans , Quality Control , Vaccines/toxicity , Lot Quality Assurance Sampling , Vaccine PotencyABSTRACT
Surface plasmon resonance (SPR) systems are widely used for detailed characterization of antibody ac-tivities including antigen and Fc-receptor binding. During the later stages of development, where the focus is to ensure that established critical quality attributes (CQAs) are maintained during cell culture, purification and formulation processes, analysis is simplified, and relative potencies are often de-termined. Here, simulation of binding data revealed that relative potency values, determined via parallel line analysis (PLA) and half maximal effective concentration (EC50) analysis accurately reflect changes in active concentration only if binding kinetics remain unchanged. Changes in the association rate constant shifted dose response curves, and therefore relative potencies, in the same way as changes in analyte concentration do. However, for interactions characterized by stable binding, changes in the dissociation rate constant did not result in any shift, suggesting that this type of change may go unnoticed in the dose response curve. Thus, EC50 and PLA analyses of dose response curves obtained with an anti-TNF-αan-tibody were complemented with the Biacore functionality for sensorgram comparison analysis, whereby changes in antigen and Fc-receptor binding profiles could be detected. Next, analysis of temperature stressed TNF-α antibody revealed that calibration free concentration analysis (CFCA) data correlated perfectly with relative potency values. Together, these results demonstrate that combinations of SPR based dose response curves, sensorgram comparison and CFCA can be used to strengthen the confidence in relative potency assessments, and suggest that SPR can potentially be used as a surrogate potency assay in the quality control of biotherapeutic medicines.
ABSTRACT
Objective@#To establish a functional antibody detection method for acellular pertussis vaccines in order to conveniently and effectively evaluate the production consistency and potency of acellular pertussis vaccine bulks and final products.@*Methods@#Chinese hamster ovary (CHO) cell clustering assay was optimized and used to measure titers of neutralizing antibodies against pertussis toxin in mouse immune serum samples.@*Results@#Vaccine samples were determined to be immunized intraperitoneally with 1/5 the human dose to ten female NIH mice (20-24 g, 5-week-old). Four weeks after immunization, blood samples were collected to isolate serum. Serially diluted serum samples were used to neutralize 0.1 IU/ml of pertussis toxin national reference product for 2 hours. Results of clustering were determined after 48 hours of incubation in pre-cultured CHO cell wells. The geometric mean of the serum dilution of the final unclustered wells was the neutralizing antibody titer of vaccine sample. There were significant differences in the titers of neutralizing antibodies elicited by acellular pertussis vaccines prepared with different manufacturing processes. Vaccine samples succeed or failed the modified intracerebral challenge assay (MICA) were easily distinguishable by neutralizing antibodies.@*Conclusion@#The method of detecting neutralizing antibodies to pertussis toxin greatly reduces the amount of animals used in research. CHO cell clustering assay that has better repeatability and precision can be used for monitoring and initial evaluation of the consistency and potency of the bulks and final products of pertussis vaccines prepared with different manufacturing processes.
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The biological potency assay and chemical fingerprint chromatogram were applied to quality evaluation of rhubarb. Using the biological potency as indicators, we evaluated the differences in quality of multiple batches of rhubarbs and related products. Using the platelet aggregation analyzer, we determined platelet aggregation rate in the different rhubarbs preparations, and calculated the biological potency based on the simplified probit principle. UPLC was adopted to establish the fingerprint spectra for rhubarbs. The spectral efficiency correlation analysis between chromatograms and biological potencies were conducted using the double variables of SPSS 22.0 software. We used three chemical composition to verify the potency. The biological potency results suggest that Rheum palmatum has a more potent activity than Rheum tanguticum, and wine-treated rhubarb had a higher potentcy than charred. We identified 10 elements in the Fingerprint Spectrum. The relevant elements including rhein-8-O-β-D-glucoside, emodin-8-O-β-D-glucoside and rhein have the strongest activity in the inhibition of platelet aggregation. In conclusion, this study provides a analytical method for rhubarb biological potency based on determination of the maximum antagonism rate model. The rhein may be the effective substance. It may serve as a reference in the quality control of wine processed rhubarb products.
ABSTRACT
Potency is one of the most important indexes of inactivated vaccines.A number of methods have been established to assay the potency,of which the NIH test and single-dose mouse protection test are the prescribed methods.Here,we report a method to semi-quantitatively assay the potency of an inactivated rabies vaccine,which uses fewer animals and takes less time to complete.Depending on the quality requirements of a vaccine(e.g.minimum potency),a rabies reference vaccine is,for example,diluted to the minimum potency,and 50 μL of the dilution is taken to inoculate 10 mice.The same amount of the test rabies vaccine is inoculated into another 10 mice.After two weeks,all mice are bled and serum samples are assayed for viral neutralizing antibody by the fluorescent antibody virus neutralization(FAVN) test.By comparing the median and interquartile range of antibody titers of the reference vaccine with those of the test vaccine,the test vaccine potency can be semi-quantitatively judged as to whether it is in accord with the required quality.The reliability of this method was also confirmed in dogs.The procedure can be recommended for batch potency testing during inactivated rabies vaccine production.