Whilst CD4+ T cell-depleted sheep had a much higher mean peak in serum IL-4 than CD8+ and WC1+ γδ T cell-depleted sheep (9.026 ng/ml, 3.161 ng/ml, and 2.639 ng/ml, respectively), this was due to high spikes in two CD4+ T cell-depleted sheep (#31/22) at peak infection (24.79 and 12.32 ng/ml) prior to euthanasia. This evidence concerns the gene IL4 and infection.