Specificity of Inhibition by Antiserum of the Development of Immediate and Delayed Hypersensitivities in Mice

The data reported in this paper confirm our previous report that hyperimmunized mice can produce antiserum which will interfere, in other mice receiving it, with development of delayed hypersensitivity and, to a lesser extent, Arthus hypersensitivity to purified proteins. They also provide direct evidence that this inhibitory effect is specific, and that the inhibitor may be a humoral antibody. It probably is not a precipitin.