CD8A and influenza: Although no statistically significant differences were observed in the levels of influenza-specific CD8 T cells induced with 103 or 104 FFU of PR8/Len, or 103 of PR8/AA (Figure 6A–C), levels of positive CD8 T cells in the lungs from mice vaccinated with 104 FFU PR8/Len and 103 FFU PR8/AA were similar - and greater than those observed in mice infected with 103 FFU of PR8/Len, correlating with the level of protection against X31 challenge (Figure 8).