Figure 5.

Antibody responses specific for H5N1 viral antigens in mice immunized with whole particle or ether-split vaccine. B6 mice were s.c. immunized with H5N1 whole particle vaccines or ether-split vaccines without adjuvant twice with a 1-week interval between injections, as described in Fig. 3. One week after the second immunization, sera were collected. Diluted sera were incubated with H5N1 viral antigens. IgG (a), IgG1 (b) and IgG2a (c) were determined by specific secondary antibodies. Averages of OD₄₅₀ absorption and standard deviations of three mice in each group are shown.