Ensuring the preventive anti-plague vaccination and the rational use of immunoprophylaxis means entail an adequate and timely assessment of their effectiveness. In the absence of mass cases of plague, it is impossible to objectively assess the actual (epidemiological) effectiveness of anti-plague vaccination means and methods, therefore, the analysis of efficacy shifts towards studying individual indicators of the immune response to the introduction of a vaccine, and the immunological efficacy of vaccination becomes a key factor that ultimately ensures its epidemiological effect. The aim of the work – as part of a comprehensive evaluation – was to determine the nature of individual immune response and characterize the group immune responsiveness of persons vaccinated against plague in order to build up a methodology for individual and group adjustment of the anti-plague vaccination regimen. Materials and methods. We used an array of information data obtained during monitoring of post-vaccination immunity in individuals immunized with live plague vaccine (LPV), presented in the form of a database. To analyze diseases in the post-vaccination period among the vaccinated population, a five-year retrospective cohort study was conducted to determine the incidence of acute and exacerbation of chronic diseases in people vaccinated and not vaccinated against plague. Results and discussion. Persons vaccinated against plague were ranked according to the level of immune responsiveness. The nature of individual immune response was revealed and the group immunoreactivity of vaccinated individuals was characterized. The possibility of predicting the intensity of the immune response to vaccination has been determined. The frequency of adverse events following immunization (AEFI) in individuals annually vaccinated against plague has been assessed. As a result of the distribution of vaccinated individuals according to the level of immune responsiveness and taking into account AEFI, the possibility of forecasting the individual and group immunoreactivity of vaccinated individuals has been determined to justify timely correction of the LPV administration regimen.