An enzyme linked immunoassay for estimation of antibodies to Newcastle disease virus strains

The sensitivity of enzyme linked immunoassay (ELISA) was compared to that of haemagglutination inhibition (HI) test in detection of humoral antibodies in birds vaccinated with Newcastle disease virus (NDV). The highest antibody titre at day 21 post-vaccination as detected by ELISA in the sera of vaccinated birds was 2560 by all strains in contrast to the HI titres of 640 to 1280. The antibody titre was higher in all pre- and post-vaccination sera as determined by ELISA than detected by HI test.