The third group of influenza strains (KY/108 and KY/110) was the most immunogenic compared to the other isolates, and differed from the two groups above in that they showed the highest levels of inflammatory cytokines late in infection (e.g., IL-6, TNF-α, IL-1β) but were similar to Group 2 in terms of lethality. Here, IL1B is linked to infection.