CALIBRATION OF JAPANESE ENCEPHALITIS REFERNCE STANDARD STRAIN NAKAYAMA

Abstract

Japanese encephalitis (JE) reference standard vaccine strain Nakayama is a production in Government level project in 2003 that has used as a biological reference in quality control of inactivated Japanese encephalitis vaccine. To ensure the quality of JE reference standard vaccine strain Nakayama, periodic calibration is very important and necessary, especially when there is a change in mouse line of routine procedure. This project used cross-sectional descriptive study in the laboratory and Plaque reduction neutralization test 50% (PRNT₅₀) is applied to calibrate JE reference standard vaccine. The result showed that the average  potency value of JE reference standard vaccine strain Nakayama was 1,665 log PRNT₅₀ and passed the criteria (≥ 1,30 log PRNT₅₀) with coefficient variation (CV) < 25%. Therefore, JE reference standard vaccine strain Nakayama is still ensured to apply for routine procedure at National Institute for Control of Vaccines and Biologicals (NICVB).