The safety of a new chemical typhoid preparation containing a complex of Vi and K antigens in tests of its acute and chronic toxicity

Acute and chronic toxicity of a new chemical typhoid preparation containing the complex of surface Vi- and K-antigens has been studied. The study has revealed that the preparation, when introduced subcutaneously and intravenously in immunizing doses in a single injection or in multiple injections, produces no toxic effect on the organs and tissues of experimental animals. In experiments of chronic toxicity the microscopic study has shown pronounced hyperplasia of the lymphoid system with enhanced macrophage reaction in the spleen, thymus, mesenteric lymph nodes and Peyer's patches in the small intestine.