OPTIMAL PROCEDURE POTENCY TEST OF IMOJEV VACCINE FOLLOWING CHANGES IN CELL STAINING AND FIXATION REAGENTS

Abstract

Imojev is a vaccine for Japanese encephalitis virus prevention and is quality controlled at National Institute for Control of Vaccines and Biologicals (NICVB) before distribution. At NICVB, the research team modified cell staining and fixation solutions to reduce testing time, save expenses, and to minimize exposure to harmful chemicals for performed staff, while still ensuring the accuracy and reliability of test results. The potency procedure for the Japanese encephalitis vaccine Imojev after modifying cell staining and fixation reagents, was partially validated based on indicators such as accuracy and precision. The results of accuracy showed that the average potency value of reference standard was 4,76 log PFU/dose, with a t-value of 1,22, which is less than the critical t-value from Student's distribution at the confidence level P = 95%. The potency values of vaccine for repeatability and intermediate precision indicators were respectively 4,82 and 4,72 log PFU/dose, within the acceptable specification by manufacturer (4,0-5,8 log PFU/ dose). Therefore, the procedure of Imojev vaccine potency after modifying cell staining and fixation chemicals, meets the established criteria and can be replaced for the previous routine testing method.