1RNA extracted from patient specimen.2Calender week. 3Clade/cluster specific substitutions in HA1 and HA2. 4A(H1N1)pdm09 virus in cluster 1 with virus specific N156K substitution.
Table 2: Cross neutralization data (HI) of current and past A(H1N1)pdm09 influenza vaccine viruses and selected A(H1N1)pdm09 viruses of the German sentinel reflect antigenic variation between A(H1N1)pdm09 N156K and other A(H1N1)pdm09 viruses