Evaluation of Akabane vaccine strains based on molecular characterization

Akabane virus causes congenital abnormalities of the central nervous system in the fetus or calf of an infected ruminant and classified into an arthropod-borne viral disease. For the purpose of quality control of an Akabane live vaccine, we identified the vaccine strains and investigated the nucleotide sequence similarity of the N gene derived from the commercially available five Akabane vaccines in Korea. The Vero cells infected with the Akabane vaccines showed specific cytopathic effects, which were characterized by the aggregation and detachment of cells. Four of the five commercial Akabane vaccine strains had identical nucleotide and amino acid sequences but the last vaccine strain had one point mutation in the amino acid sequence of the N gene. Alignment of the nucleotide and amino acid sequences showed 99.9 to 100% similarity among the five commercial vaccine strains. The Akabane vaccine strains also had high nucleotide similarity ranging from 99.0 to 99.6% with the Korean isolates, KV0505, K9 and 93FMX, respectively. Even though the live attenuated Akabane vaccines have been used in South Korea since the 1980’s, the genetic characteristics of all the commercial vaccine strains have not changed over the last 20 some years. Therefore, our results indicate that the current Akabane vaccine strains are still genetically secure and stable and well controlled during vaccine production. KCI Citation Count: 0