Postvaccinal changes in the nitric oxide system after immunization with live dry tularemia vaccine.

Immunization of outbred male albino mice with live dry tularemia vaccine in a dose of 50 CFU/mouse was associated with stimulation of the NO system and accumulation of NO metabolites (nitrites and nitrates) in splenic and hepatic tissues. High levels of these metabolites persisted by day 14 after the initial and repeated immunization. These results suggest that the immunotropic effect of live dry tularemia vaccine manifested by not only modulation of the functions of immunocompetent T and B cells, NK and K cells, micro- and macrophages, but also by stimulation of intracellular anti-infection defense at the tissue level via intensification of NO synthesis.