[The activity of NK and K cells in mice vaccinated against plague]

The activity of NK and K cells in mice immunized against plague has been studied. This activity has been shown to depend on the dose of the vaccine and the time elapsed after immunization. The booster immunization of mice leads to an increase in the specific sensitization of lymphocytes, the antibody level and to an increase in the activity of killer cells. Changes in the cytotoxicity of NK cells on days 21-28 after primary and booster immunization are considered to occur not due to the action of Yersinia pestis themselves, but as the result of the immunological transformation induced by these microorganisms in the animals.