Figure 2.

Immunized DBA/2J mice did not lose body weight and survived lethal infection with mouse-adapted H1N1 influenza A virus. Immunized and naïve female DBA/2J and C57BL/6J mice were infected with 2 × 10³ FFU/mouse PR8M virus. Body weight loss for each group of infected mice at various days p.i. (time post infection) is shown with reference to the starting weight (body weight [%]). In addition to mice that were found dead, mice with a weight loss of more than 30% of the starting body weight were euthanized and recorded as dead. Data represent mean values +/- SEM. Using the Mann-Whitney-U-test, body weight loss between immunized and naïve DBA/2J mice was significantly different (p value < 0.05) at day 3 to 6 p.i. Similarly, body weight loss between immunized and naïve C57BL/6J was significantly different at day 5 to 12 p.i. (p value < 0.05).