Summary of proteolytic cleavage and fusion data for all HAs examined.

ND - None Detected./ = Not Determined.a- The disparity in the pH of fusion is likely due to the fact that the luciferase assay was done in 0.2 pH unit increments and the syncytia assay was done in 0.1 pH unit increments.β- Values shown are percent cleavage of total HA expressed in transfected cells.*Not determined due to poor antibody reactivity.