The thing about flu shots is that the shot only vaccinates against 3 specific strains of the flu at one time (I actually have an article about it on the asthma site...
Asthma & the Flu )
The government and the CDC look ahead and try to determine which 3 strains of the flu are
most likely to hit the US in a given year, and then manufacturers produce the vaccine according to those specifics. Usually they are correct.
This year they missed! The major flu that hit most of the US was not one of the ones that was covered by the vaccine. As far as people "getting" the flu from the vaccine, this usually doesn't happen, although they can feel somewhat rotten for a day or so; but that is common with most vaccines.
The article has lots more info on side effects and dangers, and also has the links to the official sites on the flu vaccine.