Canine parvovirus type 2c in Vietnam continues to produce distinct descendants with new mutations restricted to Vietnamese variants

Viral protein 2 (VP2) of canine parvovirus (CPV) exhibits a high degree genetic and antigenic diversity. We analyzed 88 Vietnamese CPV-VP2 sequences (1755 bp), 34 from this study 54 previous studies, discovered new sublineage, “new var.”, within the lineage CPV-2c-“new”, characterized by mutation 5G/447M, which is restricted to isolates. These mutants appear have emerged in recent years, accounting for 65.5% total. With strong nodal support (98%), distinct 2c-“new-var.” sublineage (5G/426E/447M) was found be separate 2c-“new” (5G/426E/447I) 2c-(Asia)/Asia-2c lineage. Amino acid changes epitopes VP2 might led generation subvariants affected antigenicity, immunogenicity, or virulence virus, resulting vaccine failure worldwide.