Figure 1. Prolonged weight loss and elevated lung viral titers in aged mice during influenza infection. Young and aged C57BL/6 mice were intranasally infected with 500 EID50 of PR8 influenza. (A) Weight loss was monitored throughout the infection and percent weight loss was calculated from day 0 prior to infection. Significant weight loss (compared to day 0) was observed day 6 through 15 (not indicated in figure) and differences between young and aged mice were observed at time points indicated (* = p<0.05). Data shown as mean ± SEM and analyzed via two-way ANOVA with Bonferroni post hoc corrections. (B) On day 0, 3, 7, 11, and 15 whole lung tissue was harvested and RNA was isolated. Total influenza PA copy number was determined via RT-qPCR. Significant viral burden was observed following flu infection (compared to day 0, p<0.05, indicated by brackets above data) and differences between young and aged mice at time points indicated (* = p<0.05). Data analyzed via two-way ANOVA with Bonferroni post hoc corrections. Data shown from one independent experiment with individual samples as dots, mean and SEM indicated by line and error bars, respectively.