Figure 3.

A single i.m. immunization protects DBA/2J mice from subsequent lethal challenge. Female DBA/2J mice were immunized once by i.m. injection of 2 × 10³ FFU PR8M virus (1× i.m.). Immunized and naïve DBA/2J mice were subsequently infected with 2 × 10³ FFU PR8M virus. Body weight loss for each group of mice at various days p.i. (time post infection) is shown with reference to the starting weight (body weight [%]). Data represent mean values +/- SEM. Using the Mann-Whitney-U-test, body weight loss between immunized and naïve DBA/2J mice was significantly different at day 5 to 7 p.i. (p < 0.05).