Figure 6:

Lethal challenge of mice vaccinated with combined administration of NA1 + NA2 VLPs using H3N2 and H1N1 viruses. Groups of BALB/c mice were vaccinated IM in a prime-boost regimen 28 days apart with 10 µg NA1 + NA2 VLPs (5 µg NA1 VLPs + 5 µg NA2 VLPs), 10 µg NA1 VLPs, 10 µg NA2 VLPs or mock vaccinated with PBS. Mice were then challenged 28 days post-boost vaccination with either 5xLD₅₀ mouse adapted A/Hong Kong/1/1968 (H3N2) virus or 5xLD₅₀ mouse adapted A/California/04/2009 (H1N1) virus. (A) Body weight changes of mice after challenge with H3N2 virus (N=10). (B) Mortality of mice after challenge with H3N2 virus (N=10). (C) Viral titers of lung homogenates harvested at 4 days post infection with H3N2 virus (N=5). (D) Body weight changes of mice after challenge with H1N1 virus (N=10). (E) Mortality of mice after challenge with H1N1 virus (N=10). (F) Viral titers of lung homogenates harvested at 4 days post-infection with H1N1 virus (N=5). Error bars represent SEM. **=p<0.01; ***=p<0.001.