With respect to the RotaTeq vaccine strain, the G1-Lineage 2 strains showed only two amino acid differences–D97E (epitope 7-1a) and S147N (epitope PFI-2 7-2) (Table 3). Overall, the epitopes 7-1a and 7-2 were more prone to variations than epitope 7-1b among all G1 strains. The VP4 protein of rotavirus consists of nine antigenic epitopes—four (8-1 to 8-4) in VP8* and five (5-1 to 5-5) in VP5*, which together include 37 amino acids [31] and [32]. The P[8]-Lineage 3 strains from Pune showed 5-8 amino acid differences with the P[8]-Lineage 1 strain of Rotarix and 2-5 amino acid differences with the P[8]-Lineage

2 strain of RotaTeq vaccine in the VP8* antigenic epitopes (Table 4A). These comprised S146G, S190N and N196G in epitope 8-1 and N113D, S125N, S131R, N135D in epitope 8-3 as compared with Rotarix vaccine strain. With regard to the P[8] strain of RotaTeq vaccine, the Everolimus in vitro P[8]-Lineage 3 strains of this study showed three and one amino acid differences, respectively, in epitopes 8-1 (S146G, N190S, D196G) and 8-3 (N113D). Strain specific differences were noted at the amino acid positions 192, 193, 195 (epitope 8-1), and 114,

115,116 (epitope 8-3) in a few (1-5) of the P[8]-Lineage 3 strains on comparison with both vaccine strains. Epitopes 8-2 and 8-4 were completely conserved. The amino acid substitutions in VP8* region were common to all P[8]-Lineage 3 strains at both time points (1992–1993 and 2006–2008). To compare VP5* epitopes

of the P[8]-Lineage 3 strains, we used complete VP4 sequences available for four P[8]-Lineage 3 strains, NIV-0613158, NIV-06361, NIV-061060, NIV-0715880 (Table 4B). These strains showed 1-2 amino acid differences (Y386D in all four strains, S388N in one strain, NIV-061060) with Rotarix and 2-3 amino acid differences (R384S, H386D in all four strains, S388N in NIV-061060) with RotaTeq in epitope 5-1. Epitopes 5-2 to 5-5 showed no variations (Table 4B). The P[8]-Lineage 4 strains, detected in Pune during 2007 and 2008, represented a highly divergent subgenotypic lineage and showed fourteen amino acid differences (twelve in VP8* and two in VP5*) with the Rotarix vaccine strain and fifteen amino acid differences (twelve in VP8* and three in others VP5*) with the P[8] strain of RotaTeq vaccine (Table 4A and B). The variability between the P[8]-Lineage 4 and the vaccine strains was restricted to the epitopes 8-1, 8-2, 8-3 and 5-1 while the epitopes 8-4, 5-2 to 5-5 were completely conserved. Comparison of the VP7 and VP4 epitopes of the G1-Lineage1, P[8]-Lineage 3 strains reported from adolescents and adults in Pune [33] and [34], showed the same amino acid variations (data not shown) with respect to the vaccine strains as were noted in the present study (Table 3 and Table 4) for the G1-Lineage 1, P[8]-Lineage 3 strains from children in Pune. Classification (Fig.