Phylogenetic tree of influenza A(H3N2) (A) (nt78-nt1061) and B/Yamagata-lineage (B) (nt100-nt571) virus sequences of the HA gene was constructed with MEGA version 5.2 using the neighbor joining method.

Patient numbers are indicated, reference sequences for infuenza virus selected from GISAID are indicated by their accession numbers. Additionally, HA sequences from german national influenza sentinel are presented. The federal states are abbreviated as follows: Bayern (BAY), Baden-Württemberg (BWB), Berlin (BLN), Brandenburg (BBG), Bremen (BRE), Hamburg (HAM), Hesse (HES), Mecklenburg-Western Pomerania (MVP), Lower Saxony (NSA), North Rhine-Westphalia (NRW), Rhineland-Palatinate (RPF), Saarland (SAL), Saxony (SAS), Saxony-Anhalt (SAT), Schleswig-Holstein (SHO), Thuringia (THR). Bootstrap values greater than 70 are displayed on branch nodes.