Establishment of the 3rd national standard for lot release testing of the Japanese encephalitis vaccine (Nakayama-NIH strain) in Korea.

In Korea, 2 inactivated Japanese encephalitis vaccines from Nakayama-NIH and Beijing-1 strain have been utilized to date. The 1(st) national standard for lot release testing of the JE vaccine was established in 2002. The 2(nd) national standard, established in 2007, is currently in use for JE vaccine (Nakayama-NIH strain) potency testing. However, the supply of this standard is expected to be exhausted by 2015, necessitating the establishment of a new national standard with quality equivalent to that of the existing standard. Quality control tests were performed to verify that the new standard candidate material was equivalent to that of the 2(nd) national standard, proving its appropriateness for potency testing of JE vaccine. In addition, based on the results of a collaborative study conducted among 4 institutions including Ministry of Food and Drug Safety, the potency of the new national standard material was determined to be 2.69 neutralizing-antibody titer (log10) per vial. Therefore, the newly established national standard material is expected to be used for the Japanese encephalitis vaccine lot release in Korea.