Evaluation of potency test against cattle, pig in order to revision of Foot-and-Mouth Disease vaccine national assay of South Korea

Foot-and-mouth disease (FMD) causes severe economical problems in livestock industry because of rapid spread and inducing low productivity. Thus, the administration of vaccines is a highly effective method for preventing FMD. In an effort to prevent and control FMD, Korea is currently implementing a vaccination policy. Despite all the hard work, Korea is suffering from recent FMD outbreaks of serotype O. FMD vaccines were evaluated characteristics, purity, sterility, mycoplasma contamination, preservative contents, pH, safety, potency test in order to revise Korean FMD vaccine standard assay.

The DOE high potency (≥6PD50) vaccines (O1 Manisa and O 3039 strain) were used in this study. Eighteen cattle of more than 3 months old, 27 conventional pigs and 24 SPF pigs of more than 8 weeks old were vaccinated intramuscularly (6 group of animal received the two times dose, a full dose, 1/2 dose, 1/4 dose, 1/10 dose, none of vaccine, respectively). All animals were screened sero-negative before vaccination. For the serological test, blood samples were collected with the 2, 3 and 4 weeks after vaccination. All the sera were tested in virus neutralization test and ELISA.

In serological assay, mean VNT titres were dose-dependent that maens coefficient of correlation (r value) was higher in cattle and SPF pigs more than the conventional pigs. And all SN titres of three serotype were more than 1.42 log VNT (cut-off of vaccine company) in 21dpv. The results of correlation between animals were some relation to each other.

We evaluated potency of FMD vaccine about O1 Manisa and O 3039 strain in target animals. On the basis of our results, we may consider the antibody level of field animals and the present condition of FMD biosecurity in Korea. Further study is required to confirm the cut-off of FMD vaccine national assay standard based on field animal experiments.

Disclosure of Interest: None Declared.