The aim of the release testing of a vaccine batch is to show that this batch is consistent with and equivalent to the successive batches produced by the manufacturer and to the batches that have been shown safe and efficacious in clinical trials in man. The potency of the tested vaccine batch is tested by comparing the expression level of protein interest to that of the reference batch.
In vitro test system of 293T cell line.
As a part of the in vitro oral vaccine release test, the eukaryotic expression plasmid as vector coding the protein of interest is isolated, the intactness of the plasmid is checked with restriction analysis and then the plasmid transfected into 293T cells.
The level of transient expression using the test batch samples is compared to that of the reference batch applying validated semi-quantitative Western blot analysis.
Sample image of a Western blot run used for classification of the expression level after processing both test and reference batches: