The febrile and the leucocytotic response of rabbits on intravenous injection of typhoid-paratyphoid vaccine were studied in relation to the adrenal cortex.
1. After adrenalectomy the febrile response remained unaltered, but the leucocytotic response failed to appear. The latter response necessitates the presence of glycocorticoids.
2. Independent existence of “endogenous pyrogenic” and “leucocytosis-inducing factor” in response to vaccine could be demonstrated by passive transfer technique. The development of the “leucocytosis-inducing factor” has a close causal relation to glycocorticoids.
3. In the tolerant state the leucocytotic response was markedly reduced. Cortisone-pretreatment could restored it in full magnitude.
The possibility that the vaccine administered leaves a susceptible state for glycocorticoids to induce leucocytosis was mentioned. And it was suggested that this effect of vaccine will be diminished in the tolerant state.