Antibodies to foot-and-mouth disease virus infection associated (VIA) antigen: use of a bioengineered VIA protein as antigen in an ELISA.

An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to foot-and-mouth disease (FMD) virus infection associated (VIA) antigen (viral RNA polymerase) in cattle sera, was developed using a bioengineered VIA (BioVIA) protein antigen. Compared with the classical immunodiffusion test, with viral RNA polymerase purified from infected cell cultures as antigen, this ELISA was more sensitive. However, depending on the cattle population examined, sera with antibodies to viral RNA polymerase, probably due to infection with other picornaviruses, were detected. Despite these observations, the ELISA using BioVIA provided a rapid answer as to whether or not FMD virus circulated in a given herd of cattle. The main advantage of this ELISA is its absolute safety, since in no step of the antigen production was infectious or uninfectious FMD virus involved. The test can therefore be performed under normal laboratory conditions and no isolation units are needed as they are for the immunodiffusion test.