Cytokine secretion by poBMDC at 8 hpi. poBMDC were infected or co-infected for 8 h with H3N2 SwIV and SW114 or Nagasaki. Supernatants of mock, single or co-infection were analysed for cytokine secretion using ELISA. Bars are mean ± SEM of three independent experiments using poBMDC derived from three animals. The presence of significant differences (p < 0.05) between groups are represented by (a, b or c).