5 Things That Don't Prove Your Flu Shot Didn't Work

You Catch a Cold
Getting a flu shot won't help your body fend off the common cold. © Anna Bizoń/iStock /Thinkstock

You've been sneezing, you have a sore throat and you're beginning to develop a bit of a cough; don't be disappointed that this year's flu shot failed you -- it's likely you're suffering something other than the flu. The common cold is often confused for the flu, but the two illnesses aren't caused by the same thing. Additionally, only strains of the influenza virus are included in the flu vaccine. There are a few respiratory illnesses that can look a lot like colds and flu, despite being neither.

Respiratory syncytial virus (RSV), respiratory adenoviruses and parainfluenza viruses also cause upper respiratory illnesses that feel a lot like having the flu. RSV, for instance, usually develops as a cough with a stuffy nose, sore throat, earache and fever, and it can cause other conditions such as pneumonia and bronchitis. Adenoviruses also may cause respiratory infections such as pneumonia, as well as conjunctivitis (pink eye). And parainfluenza viruses are a common cause of croup in kids.