Body weight and HA mRNA expression of mock-treated and infected DBA/2J and C57BL/6J mice. a Weight loss. Mice were weighed daily. b HA mRNA expression, measured by qRT-PCR in whole lung homogenate as outlined in “Methods”. Solid lines infection; dotted line mock treatment, colored area around line standard deviation. *p ≤ 0.05 compared to untreated mice (weight loss) or compared to 6 hpi (HA mRNA); ‡p ≤ 0.05 for difference between infected and mock treated mice at the given time point. All p values were determined with Tukey’s test. This figure is adapted from Ref.  and is shown here for the purpose of clarity.