Potency Test of Diphtheria Vaccine by Using ELISA Technique to Evaluate in Mice Immune Response

Abstract

Potency test of antigen or immunizing agent is an important process test of vaccine efficacy. In Thailand, the potency test of diphtheria vaccines is a using neutralization test in guinea pigs (US potency method) which the result is the estimation value, but it cannot demonstrate the exact value. Development of immunological test in mice by using ELISA technique will get quantitative results in international unit (IU) that can use to compare with the manufacturers' test results. ELISA technique is an alternative to replace the former neutralization test (US potency method). The method validation results show that every examination result at 95% confidence level met the strength by 50-200% as adhere to the specification of World Health Organization. The immunizing level of mice to vaccines varied with diluted linearity of vaccines and parallelto standard immunizing level. The replicate test results on the same day at third times got the standard deviation (SD) and coefficients of variance (%CV) at 1.15 and 13.81 respectively; the replicate test during day was SD and %CV at 1.89 and 8.42. For the test results by two analysists explored that it got SD and %CV at 1.07 and 7.03 respectively w hich it was not statistically significant difference (p> 0.05). In conclusion, the study demonstrates that the method Products results as efficiency. It can be one in standard alternative on potency test of diphtheria vaccine to assess the effectiveness of the vaccine which it can reduce examination time and decrease
the risk of toxin exposure in the process neutralization.