3 Answers

Could be a bunch of factors. The Flu shot your doctor gave you may not be the strain that infected you. I got a FS in 2010 also. I haven't read of any major outbreak anywhere in the US so maybe you just ran into a bit of bad luck.
Feel Better

The toxic metal mercury is used as a preservative in an ingredient called thimerosal, which is used in the flu shots being given at SAIT, as well as most common vaccinations and shots.

The SAIT clinic uses a pharmaceutical flu shot that says on the vial; list of ingredients: contains 0.01% of thimerosal, which is about 25 to 50 mcg.

This preservative was found to be so toxic to pregnant women and infants, that the California State Senate became the second state in the US to pass a bill prohibiting doctors from giving vaccines containing thimerosal to pregnant women and children under three. The State passed the bill with the understanding that thimerosal may cause neurological conditions and diseases. US flu shots contain approximately 25 mcg of thimerosal.

Do not get anymore shots if you can help it (if it's not life threatening). imo

Flu shots do not work for every stain of the flu. Take Care of yourself!