Not to mention the point mutation in the receptor binding domain change, D225G, that is linked to lung destruction.
But the title is misleading: “H1N1 influenza adopted novel strategy to move from birds to humans” and “Bird influenza viruses have a variety of strategies to cross the species barrier and spread” The virus does not adopt anything and dos not have a strategy. Since the multiplication of the virus is rather sloppy and there are many mutations, with some of them having a higher probability of survival, it gives a genetic drift of the virus. But not according to any plan or design.
What I was getting at in post #21. Maybe entirely new microbes come and go without notice for their inability to survive.