Quoted from BudManPinFan:
From what I heard, the flu virus that's been going around is not the same one they developed the flu shot for back in October/November, so unless you got another flu shot with the correct virus you're not protected.
This makes sense..at least in my case. My son and I got our annual flu shot in October and have been sick for nearly 2 mos. I'm on my 2nd round of antibiotics and feeling great now but hoping to finally knock it out of the system. I Can't get updated flu shots or vaccines for my kid until we're 100%. This has been a nasty sick season.