Foot-and-mouth disease virus (FMDV) with a stable FLAG epitope in the VP1 G-H loop as a new tool for studying FMDV pathogenesis

► FLAG tag was substituted in the VP1 G-H loop of FMDV A24 Cruzeiro (A24-FLAG). ► A24-FLAG growth properties were similar to parental virus in vitro and in vivo. ► A24-FLAG was distinguishable from parental virus by multiple immunological assays. ► A24-FLAG was neutralized and immunoprecipitated by polyclonal anti-FLAG sera. ► FLAG tag was maintained after infection of the natural host without seroconversion.