MEASUREMENT OF ANTIBODY TITER TO FOWL POX VIRUS BY ENZYME-LINKED-IMMUNOSORBENT-ASSAY

The usefulness of the measurement of antibody titer to fowl pox virus (FPV) by enzyme-linked immunosorbent assay (ELISA) was evaluated in SP F chickens with or without inoculation with FPV. The optimum concentra tion of purified antigen was 10 mu g/ml of protein. The absorbance at 492 nm was less than 0.10 in the chickens negative lo FPV from 1 to 63 days old. By contrast, a higher titer was detected in SPF chickens wi th various FPVs inoculated into the wing web than in non-inoculated ch ickens. Moreover, there was no cross response to chicken sera immunize d with Haemophilus paragallinarum, Marek's disease virus, Newcastle di sease virus or infectious bronchitis virus. The titers increased after vaccination were not increased after subsequent challenge with virule nt FPV. These findings suggested the usefulness of the measurement of the antibody response to FPV vaccine by ELISA.