Figure 3. Analysis of peripheral blood lymphocyte counts shows no lymphopenia in the course of Influenza A virus infection.

C57Bl/6 mice were intranasally inoculated with 0.04 MLD₅₀ of Influenza A virus (IAV PR8/A/34) or medium (control) and repetitive blood samples on all animals were taken on different days p.i. The numbers of B220- (A), CD4- (B) and CD8-positive (C) cells in peripheral blood as determined by flow cytometry are shown as % relative to pre-infection levels. Data show representative results as means±s.e.m. of one out of two experiments with five mice per group.