The 2010-11 influenza vaccine has begun to be offered, and health officials are telling people to go ahead and take advantage of its availability early in the season. It is not too early to get your flu shot. The flu season can begin as early as October, but most commonly peaks in the January or February The Centers for Disease Control (CDC) is recommending everyone age 6 months old and older to get vaccinated as soon as possible. A shot received now will last through the flu season. Once you receive a vaccine your body begins to produce antibodies in about two weeks. The flu vaccine is reformulated every year based on the strains predicted to be most dominant, Morgan said, so a new flu shot is needed at the beginning of each season. Last year, the seasonal flu vaccine was developed before the H1N1 outbreak, and a second flu shot for that strain was required. This year, the H1N1 strain is included in the seasonal formulation.