Specificity of the Secondary Response to Protein Antigens

Abstract
Observations on the specificity of the secondary response of rabbits to a variety of protein antigens have been described. Previous immunization with one antigen will accelerate and magnify the immune response to the first injection of another antigen if the two antigens are related. Subsequent immunization with one antigen may increase the amount of circulating antibody exclusively oriented to another antigen administered earlier, if the two antigens are related. Neither of these phenomena can be elicited by unrelated antigens. Possible explanations for this degree of non-specificity of the secondary response are discussed.