I got a flu shot in the fall, and got flu for the first time in late January, despite all precautions. I was REALLY sick, 102 fever. I am just now getting energy back and I still have a little nasty cough off and on that is from that. This year's flu shot was notably not very effective.
Symptoms were HIGH fever for several days, joint and muscle aches, fatigue, no appetite (a first for me but I didn't lose weight, which is depressing) and a bad cough that is just now going away. Oh, and head cold symptoms too. Went through a lot of kleenex. The very high fever and the aches are key - it was flu, not a cold. Also lasting 8 weeks (2 weeks very sick). YUCK.