FIG 3.

Olfactory vaccination stimulates local and systemic immunity. BALB/c mice were nose vaccinated with 5 × 10⁵ PFU of either WT K181 or ΔM33 MCMV. At days 7, 14, and 28 p.i., NALT (A), SCLN (B), spleens (C), and bone marrow (D) were assessed for MCMV-specific ASCs. Tissues from unvaccinated mice were used to determine baseline numbers. Closed symbols refer to mean ASCs from WT-vaccinated animals; open symbols are from ΔM33 MCMV-infected animals (n = 5 mice per virus group). Symbols for tissue harvests on particular days p.i. are indicated and represent the mean ASCs ± the standard deviations (SD; n = 5 mice/group). Comparisons between vaccination groups were performed by a two-tailed Student t test (**, P < 0.01; ***, P < 0.001; ****, P < 0.0001). Sera from these mice were tested for IgM antibodies (E) or IgG antibodies (F) to MCMV by ELISA on the days p.i. indicated. All sera were assayed independently, and the results show the average absorbance at each dilution ± the SEM. The background absorbance of sera from unvaccinated mice was subtracted from vaccinated sera. The dashed horizontal line indicates the assay detection limit.