Figure 3From: Induction of cross-protection against influenza A virus by DNA prime-intranasal protein boost strategy based on nucleoproteinThe numbers of IFN-γ / IL-4 secreting splenic CD4+T cells in vaccinated mice. Mice were immunized as described in method section. 3 weeks after the last immunization, the number of IFN-γ /IL-4 secreting CD4+ T cells in the spleen from the different groups of mice was evaluated by ELISpot. The results represent the averages of triplicate wells of three mice, and are expressed as means ± SD.Back to article page