Sterility testing vaccines

Use in the production of vaccines As assay organisms to determine antibiotic, vitamin and amino acid concentrations Quality control of immunological products Assay methods Sterilization methods Sterilization monitoring and validation procedures Sterility testing Assessment and calculation of sterility assurance Aseptic manufacture... 

Used to validate and monitor radiation sterilization processes Vaccine against whooping cough 0.22-pm filter challenge test... 

Cross contamination of vaccines with other pathogens has also resulted in mortality and morbidity in animals. These incidents have included pseudorabies virus contaminated with pestivirus, Marek s disease virus contaminated with reticuloendotheliosis virus, contamination of cell lines and vaccines with bovine diarrhoea virus, bluetongue in dogs arising from contaminated live canine vaccine and clostridial disease in ruminants of 202 523 animals in affected herds, 41 767 were infected with Clostridium sordellii and 22 189 died, possibly as a result of a failure in a sterility test for detecting contaminants in a clostridial vaccine. 

S. Tellez, R. Casimiro, A. I. Vela, J. F. Fernandez-Garayzabal, R. Ezquerra, M. V. Latre, V. Briones, J. Goyache, R. Bullido, M. Arboix and L. Dominguez, Unexpected inefficiency of the European pharmacopoeia sterility test for detecting contamination in clostridial vaccines. Vaccine, 2006, 24, 1710-1715. 

Standardization and Testing. The final vaccine is tested for safety, potency, and residual chemicals. Safety includes testing for endotoxin and sterility. Potency is evaluated by quantitative determination of the amount of hemagglutinin in the vaccine. Antibody to this glycoprotein is associated with protection. The single radial immunodiffusion (SRUD) technique is used to standardize the mass of this protein in comparison to a reference preparation. 

Therefore quality control (QC) testing of vaccines normally includes the following assays, which must be passed prior to material being released for use in preclinical toxicology studies sterility, endotoxin, general safety, identity, mass, potency, purity, and stability [62], These assays should be performed on the final product using the clinical formulation. 

Prior to immunizations, viability tests are conducted on the vaccines by inoculating different tubes containing 10 mL of sterile Todd-Hewitt broth with 0.1,0.2, and 0.5 mL of vaccine. A tube with a sample of viable streptococcal cells is also prepared. The tubes are incubated at 37°C and growth is monitored by measuring the absorbance at 600 nm after 12, 24, and 48 h of incubation. Growth should be observed in the control, but not in the formaldehyde-treated sample. 

Nonviable cells of S. faecalis strain N were used for the immunization of rabbits to activate the immune system to synthesize antibodies. To prepare the vaccine, the cells from 500 mL of freshly grown culture were collected by centrifugation at 10,000 rpm and then shaken in 100 mL of 0.2% formaldehyde in saline for 48 h. After removal of the formaldehyde by washing the cells with 0.01 M phosphate buffer of pH 7.2 in saline, the cells were suspended in 80 mL of sterile saline. Viability tests showed that the cells were made nonviable by this treatment. This suspension exhibited high absorbance at 600 nm and was used for immunizing rabbits. 

As listed in Table 3, quality of the vaccine must again be confirmed for bulk plasmids, for the formulated, and for the filled final product. Apart from routine tests for plasmid identity, purity, and sterility, consistency of the product and process must be demonstrated in at least three consecutive runs of the entire process. These runs must result in a product that meets all predefined specifications. Stability of DNA vaccines must be evaluated by long-term studies to demonstrate that the defined specifications are met until the end of the envisaged shelf live. For naked DNA, it is not anticipated that stability will be an issue. 

Potency tests for the polysaccharide vaccines and the acellular pertussis component of the DTaP Vaccine tolerated the irradiation doses. Molecular sizing experiments indicated some size change for the polysaccharides studied. Further studies are required to determine the specific doses at which sterility is achieved, as well as to determine that the therapeutic effect of the... 

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