Figure 5

Adjuvant promoted IgG responses of mice to homologous and heterogeneous influenza H1N1 and H5N1 virus. To realize the least immunization dose of S-OIV and H5N1 vaccine needed for mice to raise sufficient protective immune responses to A/California/7/2009 H1N1 and NIBRG-14 H5N1 virus, mice (n = 3 to 4 per group) immunized with PBS, 0.01 μg, or 0.05 μg of vaccine with or without adjuvant. After 3 weeks of single-dose immunization, mice sera were used to evaluate the immune response type (A) H1N1 IgG to H1N1 virus, (B) H5N1 IgG to H5N1 virus, (C) H5N1 IgG to H1N1 virus, and (D) H1N1 IgG to H5N1 virus immune responses. The data represent the mean titers ± SD (error bars) of antibodies in each group of animals.