REVACCINATION RESPONSE OF CATTLE AS A FUNCTION OF THE 140S FOOT AND MOUTH-DISEASE ANTIGEN DOSE

Adult cattle (50) were subdivided in 2 equal groups and inoculated with foot-and-mouth disease vaccines containing either 5 .mu.g or 0.01 .mu.g of O1BFS 1860 140S antigen/3 ml dose. Four mo. later they were subdivided into groups of 5 and injected with vaccines containing concentrations of the 140S antigen ranging from 54 .mu.g-7 ng/3 ml dose. Bleedings were carried out periodically and the serum neutralizing antibody titers showed that the revaccination responses were influenced by the dose of 140S antigen in both the primary and secondary vaccinations. A linear log relationship was demonstrated between the anamnestic serum antibody log response and the dose of antigen in the secondary vaccines.