Flu season is around the corner! Protect yourself and your family this season with an annual flu vaccine for everyone in the family aged 6 months and older. While the timing of the flu season is unpredictable, seasonal flu activity can begin as early as October and last as late as May. The Centers for Disease Control (CDC) recommends vaccination by the end of October, if possible. It takes two weeks after vaccination for antibodies to develop in the body that protect against influenza virus infection.