Tracking the kinetics and magnitude of the total LCMV-specific CD4 T cell response following infection. C57BL/6, BALB/c and Swiss Webster mice were infected i.p. with LCMV and PBL were obtained at 0, 4, 5, 6, 7, 8, 10, 15, 35 and 60 days post-infection. Percentage of CD11ahiCD49d+ CD4 T cells (CD4+CD90.2+) was examined in (A) C57BL/6, (B) BALB/c and (C) Swiss Webster mice. Combined results are shown from 2 independent experiments with an n=17–18 mice per group.