Dysregulated cytokine production with age.

Serum was collected from A and O mice and assayed by ELISA for (A) CXCL9 or (B) TGFβ concentration at days 2 or 9 and 30, respectively. Data are mean + SEM (n = 3 naïve and 7–8 infected per age). (C) Human samples from IgM-positive CHIKV patients or age and sex-matched controls were assayed for Free-active TGFβ cytokine by ELISA. Data are mean + SEM (n = 39 each group). Statistical significance was evaluated by unpaired student’s t-test. * P< 0.05; ** P< 0.01; *** P< 0.001.