It won't turn you into a bird. Actually, there's lots of good news, but it's been hidden by feverishly sensationalist media. Now, for a reality vaccination.
Flu always mutates at least slightly each year.
A flu that didn't kill would never be noticed. It would just be one of myriad germs we carry that do us little or no harm. Each year on average, about 20,000 Americans die of flu. Finally, flu of course is always a virus. They usually don't suffer from it at all.