Figure 1
Survival of offspring after lethal A/PR8/34 virus challenge. The offspring were vaccinated as described in result section. One week after second immunization, the offspring were challenged with a lethal dose of A/PR/8/34 (20 × LD50). Survival rates of mice were measured after viral challenge. Panel A: (A1) Immunization of both mothers and the offspring with 1.0 μg of inactivated vaccine; (A2) Immunization of both mothers and the offspring with 0.1 μg of inactivated vaccine; (A3) Immunization of both mothers and the offspring with 0.01 μg of inactivated vaccine; (A4) Immunization of offspring born to unimmunized mothers with 1.0 μg of inactivated vaccine; (A5) Immunization of offspring born to unimmunized mothers with 0.1 μg of inactivated vaccine; (A6) Immunization of offspring born to unimmunized mothers with 0.01 μg of inactivated vaccine; (A7) Negative control. Panel B: (B1)Immunization of both mothers and the offspring with 30 μg of HA DNA; (B2) Immunization of offspring born to unimmunized mothers with 30 μg of HA DNA; (B3) Immunization of both mothers and the offspring with 30 μg of NA DNA; (B4) Immunization of offspring born to unimmunized mothers with 30 μg of NA DNA; (B5) Negative control. Panel C: (C1) Immunization of mothers with1.0 μg of inactivated vaccine and the offspring with 30 μg of HA DNA; (C2) Immunization of mothers with 0.1 μg of inactivated vaccine and the offspring with 30 μg of HA DNA vaccine; (C3) Immunization of mothers with 0.01 μg of inactivated vaccine and the offspring with 30 μg of HA DNA; (C4) Immunization of mothers with 1.0 μg of inactivated vaccine and the offspring with 30 μg of NA DNA; (C5) Immunization of mothers with 0.1 μg of inactivated vaccine and the offspring with 30 μg of NA DNA; (C6)Immunization of mothers with 0.01 μg of inactivated vaccine and the offspring with 30 μg of NA DNA; (C7) Negative control. Panel D: (D1) Immunization of mothers with 30 μg of HA DNA and the offspring with 30 μg of NA DNA; (D2) Immunization of mothers with 30 μg of NA DNA and the offspring with 30 μg of HA DNA; (D3) Negative control. *Significant differences (p < 0.05) compared to negative controls as determined by Log Rank test.