Competitive ELISA- NSP 3ABC Ab

Foot-and-mouth disease virus (FMDV) vaccines typically contain only structural proteins and do not include nonstructural proteins (NSPs). As a result, vaccinated animals generally do not produce antibodies against NSPs such as 3ABC. However, when an animal becomes infected, the virus replicates within the body, generating NSPs, including 3ABC, which in turn triggers the host's immune response to produce antibodies against these proteins. Therefore, detecting 3ABC antibodies can help differentiate between vaccinated animals and those naturally infected with FMDV.

Regarding the diagnostic window period, antibody levels peak approximately one week after infection before gradually declining. The blisters and lesions caused by foot-and-mouth disease in pigs become increasingly apparent around 3 to 5 days post-infection. At this stage, antibody titers in the pig’s blood exceed antigen levels, making antibody testing more sensitive and reliable than antigen detection.