ESTABLISHING A STANDARD OPERATING PROCEDURE FOR DETERMINING THE POTENCY OF IPV COMPONENT IN SINGLE-ANTIGEN AND COMBINATION VACCINES MANUFACTURED BY SANOFI PASTEUR

Abstract

Currently, there are three IPV component - containing vaccines available in Vietnam manufactured by Sanofi Pasteur: Imovax Polio (the single-antigen vaccine), Tetraxim and Hexaxim (the combination vaccines). Due to the differences between registration durations of various vaccines, the Department of Viral Vaccines of NICVB is attempting to find out an unified method for quality control of these vaccines. Sanofi Pasteur’s IPV vaccines are derived from the following strains: Mahoney type 1, MEF type 2 and Saukett type 3. All of them are inactivated vaccines. In this study, ELISA was used to determine the potency of IPV component. The virus antigen was diluted into appropriate dilutions and coated into a 96-well ELISA plate, then primary monovalent antibodies which are specific for each polio type were added. After that, secondary IgG antibodies compatible with the primary antibodies were used and then we read the results through the fluorescence signal. The results are calculated according to the acquired OD signals and the reference standard of known antigen concentrations. The procedure for determination of potency of IPV component was established. The testing results were expected to meet 6 evaluation criteria, in the scope of this article we would like to focus on three of them: trueness, accuracy (reproducibility) and robustness. Evaluation criteria: trueness t (type 1, type 2 and type 3) < t_α(4,303); accuracy (reproducibility) CV (type 1, type 2 and type 3) ≤ 20% and intermediate accuracy CV ≤ 20; robustness meets requirements.