EN
The level of seroneutralizing antibodies in piglets vaccinated twice with attenuated vaccine (Suivac A) or inactivated vaccine (Geskyvac) was assayed in 3 types of piggeries. Group I consisted of large piggeries free from DA in which the presence of sero-reagents was found, group II — piggeries free from AD and no sero-reagents present, group III — big piggeries in which systematic vaccination of the basic herd was being done. The studies have shown that the epizootic situation in piggeries has an influence on the dynamics and the level of specific SN antibodies in pigs vaccinated against Aujeszky’s disease.