Yes, for several reasons. First, unless you were tested for the flu virus it's possible that your symptoms actually stemmed from the common cold, sinusitis, or some other respiratory illness. And even if you're certain you had the flu, this season's vaccine protects against three strains of the virus. So getting vaccinated lowers your risk of getting sick from the other two strains.
You can even get the flu shot while you have symptoms of a respiratory illness, as long as you don't have a fever. If you do have a temperature, talk to your doctor or nurse about scheduling the vaccine for a later date. And see our advice on how to treat flu symptoms, as well as our reviews of thermometers.
It's also important to get vaccinated if you got the shot in a prior year, since the virus often differs from year to year, explains Barbara F. Young, Pharm.D., of the American Society of Health-System Pharmacists. "It is important for individuals to have a flu vaccine each year to maintain an optimal immunity as the vaccine is reformulated annually to best target the mix of influenza viruses that is expected in the coming flu season," she says.