The flu shot is made from inactivated (killed) flu viruses, which cannot cause infection. The preparation is based on flu viruses that are in circulation at the time and on flu viruses that are expected to circulate the following winter. You can get a flu shot at your doctor's office, a local clinic, drugstores, and other locations.
(Click Flu Shot to read the full eMedTV article on this topic. This resource includes in-depth information on how the flu shot works, who is encouraged to get one, and why it's important to get one each year.)