Surveillance and molecular characterization of human influenza B viruses during 2006-2010 revealed co-circulation of Yamagata-like and Victoria-like strains in eastern India

► Provides crucial information on frequency and strain diversity of Infuenza B in eastern India during 2006-2010. ► Comparison of nucleotide (nt) and amino acid (aa) sequences of HA and NA gene revealed co-circulation of lineages. ► Amino acid substitution was observed at position 198 on NA gene suggesting reduced neuraminidase inhibitor sensitivity.