Influenza phylogenetic tree for Influenza A(H3N2) sequenced by CDC

Influenza phylogenetic tree for Influenza A(H3N2) sequenced by CDC

This phylogenetic tree shows CDC’s work sequencing surveillance of just one influenza virus subtype: influenza A(H3N2). Since 2005, CDC has recorded a total of 10,000 nucleotide sequences of the influenza A(H3N2) virus that have been arranged on the tree. The tips of the branches of the phylogenetic tree are colored by geographic region, showing just how widespread CDC sequencing surveillance is. The gray bands represent the Northern hemisphere’s flu season. The chart below the phylogenetic tree shows the data on influenza A(H3N2) gathered by CDC across time, again colorized by geographical region. In 2014, after the implementation of Next-Generation Sequencing at CDC, the data dramatically increases.

CDC Influenza Division