J. White, K. Matlin, A. Helenius, Cell fusion by Semliki Forest, influenza, and vesicular stomatitis viruses. J. Cell Biol. 89, 674–679 (1981).
This work investigated the cell fusion process of representatives of 3 families of enveloped viruses. it was discovered that hemagglutinin plays a role for the influenza in the low-pH-dependent membrane fusion activity. Low-pH-induced fusion is a widespread property of enveloped animal viruses and that it may play a role in the infective process.