Immunologic Unresponsiveness to Shigella Antigens in Chickens

Abstract

Partial acquired immunologic unresponsiveness to Shigella paradysenteriae organisms and a soluble antigen derivative has been demonstrated in chickens by injection of antigen into embryos and young chicks within the period of 15-day-old eggs to 2-day-old chicks. The concentration of antigen is influential in that the greatest unresponsiveness could be obtained with the largest amount of antigen tolerated. Intravenous inoculations resulted in the greatest degree of suppression of agglutinins in comparison to intramuscular or yolk-sac injection. Unresponsiveness was finite in that under optimal conditions it lasted approximately 100 days. Antigen could not be detected during the maximal unresponsive state. Immunologic response to heterologous antigen was not measurably impaired in unresponsive birds.