Fig. 3

Protective activity of the CCFkH5-VLP vaccine against subtypes of influenza A virus. Unvaccinated and immunized mice were lethal challenged with PRH1 and HKH5 viruses one week after administration of the third vaccination. Survival rate and change in body weight were observed for 14 days. (a) Survival rates and (b) change in body weight in PRH1 virus challenge. (c) Survival rate and (d) change in body weight in HKH5 virus challenge. Protective activity against AiH3 virus was evaluated with viral titer in lung at four days post infection (4 dpi). The lung viral titer was compared across (e) immunization routes and (f) vaccine forms. Each group contains five mice and immunization methods were indicated as unvac: unvaccinated, IP: intraperitoneally, IN: intranasally and IN + SO: intranasally with sesame oil. Statistical analysis was performed using pairwise Welch’s test and the p-value was adjusted using the Bonferroni method, and the asterisk indicates statistical difference (*: p < 0.05, **: p < 0.01)