At the same time, the clear synergistic effect for simultaneously neutralizing IFN-γ and IL-6, as predicted by the mathematical model, was not observed in vivo as additional neutralization of IL-6 abolished the positive trend observed for IFN-γ neutralization following co-infection with 0.32 TCID50 IAV and 1 × 106 CFU S. pn. The gene discussed is IL6; the disease is coinfection.