The recent Foot-and-Mouth Disease (FMD) vaccines are highly concentrated inactivated virus preparations produced by filtration. As the vaccines are considered to contaminate an extremely low quantity of the non-structural (NS) proteins of the FMD virus (FMDV), the presence of the proteins can be used to differentiate infected from vaccinated animals.
FMDV NS proteins that were coded by 2AB, 2B, 2C, 3ABC and 3D genes were expressed individually using the Baculovirus expression system. The expressed proteins were confirmed by Westernblot (WB) analysis with FMDV sero-positive and negative standard sera. The reactions of the NS proteins with each 15 sera of infected and vaccinated cattle were examined by WB analysis. The 2C and 3ABC proteins did not react with the 15 sera from vaccinated cattle and only reacted with 10 and 6 sera, respectively, out of 15 sera from infected cattle. In order to differentiate FMDV-infected sera from sera exposed to FMD vaccines by WB analysis, the combination of the 2C and 3ABC proteins was found to be the most effective.
(Diagnosis Section, Department of Exotic Diseases TEL +81-42-321-1441)
Sakamoto et al. (2002) Rec.Sci. Tech. OFF. Int. Epiz., 21(3):459-463.