[Safety and immunologic effectiveness of polyantigen from shigellae for oral immunization of monkeys]. / Izuchenie bezvrednosti i immunologicheskoi éffektivnosti poliantigena iz shigell pri peroral'noi immunizatsii obez'ian.

Clinical, morphological, and immunological study was carried out in monkeys given shigellae antigen in tablets orally. Each tablet contained 0.5 mg of the antigens obtained by Boiven's method from Sh. flexneri 2a, 3, 4a, 4b, 6 and Sh. sonnei. Daily administration of the preparation for 4 days and then 4 times at the interval of 5 days proved to be harmless for monkeys. A marked immunomorphological reaction in the form of hyperplasia of the lymphoid elements of the wall of the large intestine and the lymph nodes occurred in response. There was found a resistance of the great majority of the immunized animals to the infection with the virulent Sh. flexneri 2a strain, this corresponding to the accumulation of cells secreting IgM and IgA in the wall of the large intestine.

Oral immunization of monkeys with polyvalent dysentery vaccine.

Macaca mulatta monkeys were immunized orally with polyvalent Boivin extract of Shigella flexneri 2a, 3a, 4a, 4b, 6 and Shigella sonnei. The total immumizing dose for each component was equivalent to 1.2 X 10(12) cells. After challenge with 7.5 X 10(10) cells of a virulent S. flexneri 2a strain, out of 20 immunized animals 2 developed dysentery and 4 showed mild dyspepsia; all 6 control animals became ill with dysentery. Vaccination failed to influence the incidence, duration or the intermittent character of shigella excretion. Protective antibodies appeared in high titre in the serum of immunized animals.