Studies on Immunity in Experimental Shigellosis: Special Reference to Local Antibody and Its Nature

摘要

Utilizing the pathological change induced in the ligated intestinal loop of rabbits as the experimental model for dysentery infection and the inhibition of the pathological change as the protective immunity, we compared the capacity of intravenous immunization and oral immunization to induce the protective mechanism. Oral immunization induced strong protective mechanism while intravenous immunization did not. And the best protection was obtained when rabbits were immunized with more than 600 mg of aceton dried vaccine by two series of immunization, i.e., three successive days immunization was repeated with three weeks intervals. The immune mechanism was appeared after 4 days of the last immunization and reached its maximum at 7 to 10 days, but began to fall after 21 days, and could not be proven at 5 weeks. The protective mechanism has no correlation with circulating antibodies, but coproagglutinin titer paralleled with it to a certain extent. Orally immunized rabbits had the protective capacity even when the coproagglutinin titer was low, and presence of other mechanism than coproagglutinin was suggested. (Author)