EXPERIMENTAL HUMAN BACILLARY DYSENTERY

Abstract

We⁶ have previously reported the results of studies in animals and man with single strain and mixed bacillary dysentery vaccines inactivated by exposing continuously flowing thin films of organisms to a powerful source of Schumann ultraviolet for a fraction of a second.⁷ These irradiated dysentery vaccines did not cause severe reactions in man even when given in doses of 4.8 billion per injection. They evoked in mice a very significant degree of immunity; in most cases the immunized animals resisted 100,000 or more LD₅₀ challenge doses of living organisms. Mouse protective antibodies were also increased significantly in both men and mice. However, in our previous paper we stated that "these results are not direct evidence that the dysentery vaccine is an effective immunizing agent in man. The value of irradiated or any dysentery vaccine can be determined only by a controlled experiment in human volunteers immunized and