Figure 4. Cross-Protective Effects of huN1-Immune Serum against H5N1 Influenza.

Mice were passively immunized with serum from mice that had recovered from H5N1 influenza virus infection (post-H5N1), were vaccinated twice with huN1 DNA (N1 DNA), or were vaccinated twice with saline alone. Eighteen hours after passive immunization, recipient mice were challenged with 10 MLD₅₀ of A/Vietnam/1203/04. Changes in mean weight (left graph) and survival (right graph) were monitored over 24 d. The difference in survival between recipients of serum from huN1 DNA-vaccinated and saline control mice was statistically significant (p = 0.037). Error bars represent standard deviation values. Statistical comparison is by Fisher's exact test.