Figure 3

Diagram of the reassortment events that generated the H1N2 SIVs types currently circulating in Europe. The line represents time in years. The reassortment events that involve the HA gene are reported in the upper part of the diagram whereas those of the NA gene are in the lower part. The numbered reassortment events are the following: 1- the EU H1N2 SIVs was launched with the introduction of the NA gene from the Human H3N2 viruses; 2- the introduction of the HA gene from the human H1N1 viruses that generate the EU H1N2 SIVs and the Italian group A; 3- Introduction of an H1 avian like from the EU H1N1 SIVs in the H1N2 lineage that have given rise to the reassortant H1avian-likeN2 strains and the Italian group C; 4- Introduction of the NA gene from the more recent human H3N2 viruses that generate the Italian group B; 5- Introduction of the NA gene from the EU H3N2 SIVs that generate the reassortant H1N2(EU H3N2 SIVs) strains and Italian H1avian-likeN2(EU H3N2 SIVs). Mean estimates of TMRCAs with 95% credible intervals for each event are reported.