[Delayed local reaction (DLR) after BCG vaccination in mice. II.--Correlations with the immune response (author's...

The occurrence and intensity of the DLR were correlated with different parameters of the specific and non-specific immune response induced by the inoculation of viable BCG into the footpad. A good parallel exists between the occurrence of the DRL and effector mechanisms which tend to limit the growth of BCG in the draining node, and also with the appearance of tuberculin hypersensitivity measured in vivo by skin-test. Nonspecific immunity induced in mice after subcutaneous BCG injection was measured using the relative spleen weight, and this correlates well with the onset of the DLR. Delayed type hypersensitivity (DTH) to varying doses of sheep red blood cells (SRBC) injected intravenously in normal or in subcutaneously BCG-pretreated mice indicated a functional increase of the reticuloendothelial system activity, 14 days after BCG injection. Lastly, the degree of adjuvanticity induced by BCG vaccination to DTH against SRBC which were injected in the same footpad, was strictly correlated with the kinetics of the DLR. The value of measuring DLR in mice is discussed concerning the evaluation of the immunogenicity of BCG vaccines and slso the host's capability to mount an immune response after subcutaneous BCG injection.