Fig 3. Alignment of HA proteins obtained at screening, the 1^st and 2^nd sampling round and from the vaccine strain (Haselünne/IDT2617/2003 (H1N1)).

Dots indicate identical amino acids among the HA proteins, whereas a green background indicates differences between at least one of the four HA proteins. The colored underlines represent the five antigenic sites Sa (purple), Sb (green), Ca1 (blue), Ca2 (orange) and Cb (red).