CD8A and infection: Depletion of CD8 T cells in the sequential infection group had some effect on protection from weight loss; on day 6 post A(H1N1)pdm09 virus challenge 3 out of 6 mice had lost >6.5% weight while in non-depleted mice the most severe weight loss was 2.1% and was observed in a single mouse only (Figure 6A, LV).