The possible side effects depend on which type of vaccination you get. There are two ways to be vaccinated against the seasonal flu: You can get the intramuscular injection (commonly called the flu shot) of inactivated influenza, which contains killed virus. Or you can get the nasal spray vaccine (also known as FluMist), which contains live but weakened influenza vaccine.

The flu shot can cause a sore arm, and it sometimes causes mild fever and achiness. The nasal vaccine has been linked to symptoms such as runny nose, cough, and sore throat.

Both vaccine types contain traces of chicken eggs, which can be a problem for those with egg allergies.

According to government reports, the new H1N1 influenza vaccine (for what used to be known as swine flu) will also be available both as a shot or nasal spray, and the side effects should be similar, though we don't know yet for certain.

It's not uncommon to notice some mild side effects in the days after you get a flu vaccine, but experts unanimously agree that the benefits of vaccination vastly outweigh the risks. Remember that, on average, every year 36,000 Americans die from seasonal influenza, and the new H1N1 virus could easily take a similar toll.

Talk to your doctor to help you decide which form of vaccination makes the most sense for you.