title: In vitro comparison of foot-and-mouth disease virus subtype variants causing disease in vaccinated cattle.
abstract: Foot-and-mouth disease virus isolates of types O, A and SAT 2, from diseased animals in herds routinely vaccinated twice a year were compared antigenically with the vaccine strains in the complement-fixation, neutralization and radial immunodiffusion tests. It was found that strains which had readily infected vaccinated cattle had R values against the vaccine strain in the complementfixation and radial immunodiffusion tests of 30 or less, while strains causing primary outbreaks with little spread had R values of 30-40. Threefold differences in humoral neutralizing antibody concentration between the field variant and the vaccine strain in sera from vaccinated animals were likely to be significant in terms of protection.
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000302:isolation & purification*; D005537:Aphthovirus / Q000145:classification / Q000472:pathogenicity*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000517:prevention & control*; D005536:Foot-and-Mouth Disease / Q000276:immunology* / Q000517:prevention & control; D014765:Viral Vaccines / Q000592:standards / Q000627:therapeutic use
chemical_list: D000956:Antigens, Viral; D014765:Viral Vaccines