Figure 3.

Immunization protects against homologous challenge. CB6F1 mice were immunized once with varying doses of H1N1 antigens. Antibody was measured prior to challenge (A) with A/California/7/2009 (H1N1pdm09), weight loss measured daily (B). Mice were immunized twice with varying doses of H1N1 antigens. Antibody was measured prior to challenge (C) with A/California/7/2009 (H1N1pdm09), weight loss measured daily (D). Points represent individual animals (A,C) or means of n ≥ 4 animals ± SEM (B,D). Panel (B) *p < 0.05 between 1.5 µg and naïve group and #p < 0.05 between 1.5 µg and 0.02 µg group. Panel (C) **p < 0.01.