However, as both IL-7Rα449F and Dmu mice have reduced number of baseline CD4 and CD8 T cells in the spleen and lung prior to infection (Figure S3) we examined the frequency of CD8 T cells that recognize the virus with MHC class I tetramers containing immunodominant viral epitopes NP366–374 and PA224–233[25], [26]. Here, CD4 is linked to infection.