Differentiating foot-and-mouth disease virus-infected from vaccinated animals with baculovirus-expressed specific proteins.

Abstract We had shown in preliminary studies with a small number of animals that antibodies against 2C could be detected in cattle and pigs which had been infected with FMDV but not in animals which had been vaccinated against the disease. To determine whether this test was generally applicable, seta from several hundred animals which had been vaccinated with different products in many countries have been tested in an ELISA using baculovirus expressed 2C. Our results show that only 1–2% of the sera gave a positive reaction by this method. In contrast, 100% of sera from convalescent animals gave a positive reaction. To be useful in differentiating between convalescent and vaccinated animals it is necessary to know how long these antibodies can be detected by our ELISA. We have determined the levels of antibodies against 2C and also other virus‐specific proteins which are present in cattle and pigs following infection with FMDV. Our results show that levels of anti‐3ABC antibodies could be detected by ELISA...