The above results show that for viruses with a wt capsid (i.e., O1K-A WT, and O1K-Asia WT) that infect BHK-21 cells relatively well, the introduction of aa changes at icosahedral 5-fold symmetry axes or at the canonical HS binding site appears to increase the rate of CPE, but does not significantly improve virus yield, whereas when the changes are introduced into viruses (i.e., O1K-O WT and O1K-SAT2 WT) with a wt capsid that show poor infection of BHK-21 cells, both the rate of CPE and virus yield are greatly enhanced. Here, SAT2 is linked to infection.