Heat map indicating virus neutralization profiles after secondary infection against a complete panel of H1-H12 and H14-H15 antigens for the different treatments (only antigens with positive MN included).

<p>Each box indicates a sample from an individual and the colors indicate the MN titers based on the legend. The challenge groups are indicated on the horizontal axis while the vertical axis indicates the antigens used in the neutralizations and their phylogenetic relationships. The homologous challenge 5- week interval is indicated by a *, 11- weeks by § and 15- week interval by &.