Figure 5. Body weight changes and survival of mice infected with wild type or mutant TY93/H5N1 viruses.

BALB/cByJ mice were infected with different doses (1–10⁵ p.f.u.) of wild-type virus or the indicated polymerase mutant. Body weight was monitored daily; mice that lost >35% of their starting weight or showed signs of severe disease were euthanized. Numbers shown indicate the number of surviving animals.