FIG. 3.

Cell-mediated immune response to LC16m8 and Dryvax. Groups of three mice were inoculated with PBS, LC16m8, or Dryvax, and splenocytes were obtained 1 week or 6 weeks later and restimulated in vitro with vaccinia virus strain WR at a multiplicity of infection of 1.0. Cells were harvested about 18.5 h poststimulation (including a 2.5-h incubation in the presence of brefeldin A) and stained for primed CD4⁺ and CD8⁺ cells expressing IFN-γ. The percentages of primed CD4⁺/IFN-γ⁺ and CD8⁺/IFN-γ⁺ spleen cells at 1 week and 6 weeks postimmunization for three mice in each group were averaged. Error bars represent standard deviations.