[Demonstration of specific VIA antibodies in foot-and-mouth disease].

Experiments were carried out to obtain a specific VIA antigen of F.M.D. During the research, 7 series of VIA antigen were extracted with high purity and specificity. It was established that 90% of the infected animals build specific VIA antibodies against F.M.D.V. Up to 70% of the repeatedly vaccinated cattle against F.M.D. contain VIA antibodies. The percentage of the positive reagent depends on the age of the animals, on the number of the immunizations and on the sort of the used vaccine. The cause for the high percentage of the seropositive to VIA not vaccinated animals is not elucidated.