Revenson and Segura [116] reported that FMDV grew well on BHK-21 cell line enabling large-scale production of antigen with good complement fixing properties. The BHK-21 cell culture provides better growth for FMDV than the suspension culture [115, 117, 118] . It has also been reported that with subsequent passage in BHK-21 clone 13 cell line, the titre of FMDV increased significantly [108] . Nair [112] reported that the susceptibility and infectivity titers of IBRS-2 and MVPK cell lines were less as compared to BHK-21 cells, and thus had no advantage over BHK-21 cell line for vaccine production. Mishra et al. [119] also adapted FMDV field isolates to BHK-21 clone 13 cells in 3-7 serial passage.