In the present study, the inactivated vaccine adjuvanted with the combination of MPL and poly I:C provided enhanced protection and reduced inflammation at the infection site (Fig. 2), but it also possibly increased Th1-polarized immune responses, as evidenced by the increased levels of antigen-specific IFN-γ and IL-4 (Fig. 5E–H), which provided sufficient protection against illness severity due to viral infection40. The gene discussed is IL4; the disease is infection.