Most significant changes in selective pressure. Locations with significant probability of a given substitution-matrix change are tabulated.

The magnitude of the probability of a change are given as 0.3 to 0.4 (italics), 0.4 to 0.5 (normal), and 0.5 and above (bold). Because it is difficult to separate the transitions from EN72 to VI75 and TX77, the transition between these three states are considered a single transition. Antigenic region (where appropriate) is indicated.