The common ancestor of HRSV diverged from Bovine RSV at about 550 years ago.
HRSV-A diverged from HRSV-B at about 280 years ago.
The present HRSV-A strains could be phylogenetically assigned as 6 genotypes.
Amino acid substitutions were not significantly linked to the epitope of the palivizumab.
The effective population size of prevalent genotype increased during the last 10 years.