Fig 4. Body weight and survival rate of mice following lethal challenge with influenza virus.

At 18 days following the last immunization, all mice in study group B were intranasally challenged with 10 LD₅₀ of H1N1/A/TN/1-560/2009-MA2 virus. (A) Body weight and (B) survival of mice orally immunized with PBS, LL-HA1/L/AcmA or HA1/L/AcmA, or subcutaneously immunized with HA1/L/AcmA-FA, was monitored daily for 14 days following virus challenge. The body weight of mice on the day of viral challenge was used as the baseline weight to determine the body weight changes post-viral challenge. Asterisks indicate statistically significant differences in comparison with the PBS-treated group (*p<0.05; **p<0.01; ***p<0.001).