Figure 4. NE enhanced protective immunity of H5N1 vaccine.
Female Balb/c mice (6–8 weeks old, 5 mice/group) were immunized with two doses of H5N1 subvirion vaccine (0.1 µg) or NE-adjuvanted vaccine (0.1 or 0.01 µg) or NE alone 4 weeks apart. Four weeks following boost immunization, mice were challenged with 5 LD50 of homologous strain of H5N1 virus, rgA/VN/04 (A) and heterologous strain, rgA/IN/05 virus (B) and mortality was monitored (square H5N1 0.1 µg; diamond H5N1 0.1 µg+NE; circle H5N1 0.01 µg+NE; open square NE alone). The data are representative 2 independent experiments.