SAA time course in C57/BL2, Swiss-Webster, and DBA.2 mice infected with influenza A/California/04/09 (H1N1)pdm09 virus and effect of antiviral treatment on SAA levels. Mice (n=20) were intranasally infected (1LD100) and treated with oseltamivir (+ 4 hpi, 20 mg/kg/d, bid × 5). At specific time points (0-7 dpi), animals were cheek-bled for serum collection. The experiment was terminated 14 days post-virus inoculation. Survival and body weight were monitored daily (data shown in Supplement Figures S3-5). SAA peaked at 3dpi. Data are presented as mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 compared to placebo; two-way ANOVA with Sidak's multiple comparison test. Oseltamivir treatment reduced mean SAA levels at 3 dpi, but only significantly in (F) P = 0.0056. Unpaired t-test with equal SD.