Figure 2: H1-DNA/SV09 confers only partial protection while three times SV09 protects against heterosubtypic H5N1 challenge. Mice were immunized either 3x with Inflexal 2009 (3xSV09), 3x with H1 HA DNA followed by a boost of Inflexal 2009 (H1-DNA/SV09) or 4x PBS (PBS) followed by challenge with H5N1 A/Hong Kong/ 156/97 (n=8 for PBS and 3x SV09; n=7 for H1-DNA/SV09). Kaplan-Meier survival curves (left) and means bodyweight change (right). Error bars indicate 95% confidence interval (bodyweight).