While it is important to get vaccinated against the flu virus as early as possible, it is never too late to reap the benefits of this vaccine. According to The Centers for Disease Control and Prevention, the peak months for the spread of the flu virus are January and February and the season can last into mid-May. Those at highest risk of complications from the flu are young children; people 65 and older; pregnant women; and people with health conditions such as heart, lung or kidney disease, or a weakened immune system. "Adults age 65 and older face the greatest risk of serious complications and even death as a result of influenza. That is why it is so important that they get immunized. Even when older adults contract the flu after immunization, which can happen, those cases tend to be less severe and of shorter duration," says Dr. Mark Lachs, director of geriatrics at NewYork-Presbyterian Hospital.