CD8⁺ T-cell reactivity to whole virus is superior compared to split virus preparations.

<p>CD4⁺ and CD8⁺ T cells purified from PBMC of healthy individuals were screened for IFN-γ ELISpot reactivity to autologous DC pre-loaded with 10 µg/mL of influenza whole virus and related split virus vaccine formulations. DC also received maturation cytokines during vaccine pulsing. (A) Representative data obtained from donor HD20 with 1×10⁵ CD4⁺ T cells (grey columns) or 1×10⁵ CD8⁺ T cells (black columns) plated per well are shown. (B, C) Reactivity to influenza whole virus and related split virus vaccines were measured in 10 randomly selected healthy individuals as described in (A). Box plot diagrams include IFN-γ ELISpot data from purified CD4⁺ (B) and CD8⁺ (C) T cells. Effective SFC were determined by subtraction of background spot numbers (w/o vaccine) from spot numbers induced by each individual vaccine. <i>P</i>-values were calculated by two-tailed paired-sample Wilcoxon signed-rank test.