Figure 7.

Lung tissues (n = 3) were collected from challenge-infected mice, and plaque assay was performed to quantify lung virus titer. (A) Lung homogenates of VLP-immunized mice challenged with 10 LD₅₀. (B) Virus titers of mice challenge-infected with 2 LD₅₀. Data are presented as median ± SD (* p < 0.05, ** p < 0.01) and are representative of the two independent immunization studies conducted on mice. Abbreviations: Naïve + cha—unimmunized infection control; HA VLPs—virus-like particles (VLPs) expressing hemagglutinin (HA) antigen only; NA VLPs—VLPs expressing neuraminidase (NA) antigen only; HANA VLPs—VLPs expressing both HA and NA antigens; M1 VLPs—VLPs expressing only M1 antigen.