It won't turn you into a bird. Actually, there's lots of good news. Alas, once again the urge to sensationalize health news has made the media feverish. 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 zillions of viruses we carry around 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 suffer little from it or not at all.