M2-2 gene as a new alternative molecular marker for phylogenetic, phylodynamic, and evolutionary studies of hRSV

•M2-2 gene is a phylogenetic marker and classify hRSV within the clades A and B.•Clade ancestors originated before by analysis with the M2-2 gene rather than G gene.•M2-2 gene shows that hRSV went through a genetic bottleneck event in the 2000s.•M2-2 gene is under the effect of purifying selection.