In fact you are more or less correct. It is as if they put in dogs and got out cats. That's just how Influenza works. It mutates, adapts, and evolves extremely

In fact you are more or less correct. It is as if they put in dogs and got out cats. That's just how Influenza works. It mutates, adapts, and evolves extremely rapidly. This is why it never has been, and likely never will be, eradicated (notice that those "in the know" don't even talk about Influenza eradication in passing).