Comparison of a kinetic-based enzyme-linked immunosorbent assay (KELISA) and virus-neutralization test for infectious bursal disease virus. I. Quantitation of antibody in white Leghorn hens.

The kinetics of the enzyme-substrate reaction served to evaluate a single-serum-dilution indirect enzyme-linked immunosorbent assay (ELISA) for quantitating antibody in white leghorn hens inoculated with infectious bursal disease virus (IBDV) vaccines. The antibody profiles of primary and secondary responses induced by two IBDV immunization regimens were compared using a kinetic-based ELISA (KELISA) and the virus-neutralization (VN) test. KELISA was standardized with an IBDV-infected VERO cell suspension. Antigen was capable of binding minute quantities of sample (5 microliter) without requiring dilutions. Conjugate consisted of immunoglobulin G fraction of goat antiserum against chicken IgG bound to horseradish peroxidase. Neither test revealed a difference in antibody profiles between the two immunized groups. The KELISA was as efficient as the VN test in detecting antibody after vaccination and one log 2 unit more sensitive. The KELISA was suitable for testing large numbers of samples (n = 60) in a microplate compared with a conventional ELISA (n = 8).