Figure 1.

Proliferative response of peripheral blood mononuclear cells (PBMCs) obtained from vaccinated with live plague vaccine (LPV) (A-Total, A-recently vaccinated (RV), A-early vaccinated (EV)) and unvaccinated (group B) donors induced to in vitro F1 and LcrV stimuli. PBMCs were stimulated with either a recombinant F1 or LcrV (both at 5 μg/mL), or concanavalin A (ConA; 1 μg/mL) as a positive control. Stimulation indices were calculated as mean counts of quadruplicates in antigen-stimulated cultures divided by the mean counts of quadruplicates in unstimulated cultures. Results are expressed as min to max (whiskers) with the median designated as a horizontal line, and the box extends from 25th to 75th percentiles. The Mann–Whitney test was performed for statistical analysis; ns: not significant.