The flu can be serious and may require care in a hospital. Some people who get the flu could die. What is the best way to prevent flu? The single best way to prevent the flu is to get the flu shot. Everyone 6 months of age and older should get the flu vaccine every year. The flu shot cannot cause the flu. The flu shot is given with a needle, usually in the arm. It can be given to people 6 months of age and older. Why do I need to get the flu vaccine every year?