FIG. 6.

MHC class I-restricted CD8 T cells significantly contribute to heterosubtypic protection after CLDC-adjuvanted vaccination. CLDC-PR/8/34 vaccine was administered twice i.m. to wild-type mice (WT CLDC; n = 9) or mice with targeted deletion for MHC class I (K^bD^b−/− CLDC; n = 10) of the C57BL6/J background. Mice were inoculated i.n. with 240 hemagglutination units of influenza A virus strain HKx31 on day 10 after the second vaccination. A separate control group of wild-type mice who had not been immunized (Unvaccinated; n = 9) were similarly inoculated. Each symbol shows the log₁₀ of the TCID₅₀/ml of lung homogenate from an individual mouse obtained on day 4 of infection, with the mean value for the group indicated by the horizontal bar. P values were calculated using the unpaired, two-tailed Student t test with Bonferroni's correction for multiple comparisons.