comparison of this primary structure and the deduced amino acid sequence with the haemagglutinin gene and protein of strains belonging to the same ( h3 ) subtype and to different subtypes , of both human ( h2 ) and avian ( hav1 ) origin , documents further at the molecular level the two independent modes of antigenic variation of the virus -- drift and shift .
C0086418
human
C0919509
h2