Shifting patterns of RSV-A NA1 lineages were observed in 2010–2012 seasons. RSV-A ON1 lineage 1 with E262K appeared as the major genetic cluster in 2012. Vietnamese RSV-A ON1 and NA1 were evolving with the faster substitution rates. N-glycosylation patterns within G gene of Vietnamese NA1 shifted every year. N-glycosylation pattern of Vietnamese NA1 and ON1 strains were distinct.