Induction of tolerance in chickens by low doses of human serum albumin administered after hatching.

The possibility was tested whether tolerance can be induced in newly hatched chickens by a single injection of HSA on the day of hatching in doses one or several orders lower than the dose employed in previous experiments (100 mg of HSA). Doses of 10 and 1 mg of HSA induced a statistically significant suppression of anti-HSA antibody formation after challenge at the age of 2 and 4 weeks. Injection of 0.1 mg of HSA into newly hatched chickens also produced a statistically significant decrease in antibody formation after challenge at 2 weeks of age.