Can a Flu Shot Give You the Flu?

Q: Can a flu shot give you the flu?

A: No. Since the flu shot contains killed virus, it's not possible to get influenza from this vaccination. The less commonly used nasal vaccine (also known as FluMist) does use a live but very weak virus. Although it's theoretically possible that someone could get influenza from the nasal vaccine, this has not been seen in the big trials that studied it.

According to government reports, the new H1N1 influenza vaccine (for what used to be known as swine flu) and the seasonal flu vaccine each will be available as both a shot and as a nasal spray.

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

It's not uncommon to notice some mild side effects in the days after you get a flu shot, 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.

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