IFNG and influenza: In contrast, CD4+ memory T-cells responding to influenza stimulation, in the absence of carriage, were detectable in almost all BAL samples (Figure 1B and Figure S1 in the online repository) and these cells were TNF+ (0.33±0.21% vs media control 0.1±0.06%, p = 0.006, paired T-test) and IFNγ+ (0.27±0.22% vs media control 0.07±0.05%, p = 0.03, paired T-test) CD4+ memory T-cells, consistent with a Th-1 phenotype.