As soon as the vaccinesbecome available, which is usually by September or October of every year. For the fall of 2010, the usual seasonal flu vaccination will include protection against the H1N1 virus (formerly known as swine flu), which is still expected to be active during the 2010-2011 flu season. Remember, it usually takes about two weeks for the body to develop protective antibodies in response to a flu shot. That's why it's good to get vaccinated sooner rather than later. The Flu Resource Center can help you find out where to get a flu shot near you. The American Lung Association also offers a Flu Clinic Locator.