Enhancement of immunostimulating and immunotherapeutic effect of BCG vaccines using listerial endotoxin-like substances.

On the basis of experience with the immunomodulating effect of the endotoxin-like component of Listeria monocytogenes, designated factor Ei, the time parameters concerning the onset and duration of hypersensitivity induced by listeriae, mycobacteria and their components were compared. Their differences, just like different mechanism of their effect, following their simultaneous and repeated administration, furnish means of significantly enhancing the anti-tuberculosis and anti-tumor effect of strong BCG vaccines in animal experiments. This enhancement of effect makes it possible to lower the number of BCG doses otherwise required to produce the same or similar results.