Influenza vaccination induces vaccine-reactive CD4 T cells in pregnant women 9–15 days after vaccination.

<p>(A) Frequency, among total CD4 T cells, of CD4 cells producing any of the cytokines IFNγ, IL-2 or TNFα after Fluzone stimulation (6 hours). (B-D) Frequency of CD4 T cells producing IL-2 (B), TNFα (C) or IFNγ (D) among total CD4 T cells after Fluzone stimulation. Horizontal lines indicate median values. P values are determined by Wilcoxon matched-pairs signed rank and Mann-Whitney tests.