Abstract
Summary
In order to assess the mechanisms of host resistance to Newcastle disease virus (NDV), the susceptibility of young adult normal, T cell deficient and agamma-globulinemic chickens to an avirulent live vaccine (Bl) and a mesogenic strain of NDV was studied. All animals, regardless of im-munological status resisted the vaccine strain. Most normal birds resisted mesogenic NDV, however T cell deficient birds were much more susceptible and agammaglobu-linemic chickens were extremely susceptible. There was no difference in the kinetics and levels of hemagglutination-inhibition activity of plasma between normal, control-irradiated and T cell deficient birds ncr between dying and surviving birds. Agammaglobu-linemic chickens could be partially protected against an otherwise lethal challenge following immunization with avirulent NDV, low doses of mesogenic NDV inoculated intranasally or im injection of β-propriolactone inactivated NDV mixed in complete Freund's adjuvant. The possible mechanisms for this protection together with the relative roles of humoral, cell mediated and nonspecific immunity are discussed.
Get full access to this article
View all access options for this article.