Abstract

This document presents the results of a validation study to the use of a single dilution assay in potency testing of the diphtheria component of DPT-polio vaccines. Based on historical data of multi-dilution assays on 27 consecutive batches a simulation study was performed to test the actual performance of a single dilution assay. Results were statistically analysed by means of the Student's test. From the study it is concluded that the single dilution assay in diphtheria potency testing of DPT-polio vaccines can be a valid procedure to demonstrate that products exceed the minimal requirements given for potency provided that consistency in production and testing has been proven.