How Kids Flu Shots Work
Flu shots protect kids in the same manner as they protect adults. Once you are vaccinated, your body makes proteins called antibodies, which can recognize and fight the flu if you are exposed to it. The flu vaccine is made to fight against specific flu viruses that may be circulating during each flu season. Since flu viruses are constantly changing, vaccination last year may not protect you from the flu this season. In fact, it may not protect you against strains of the flu circulating this season if they are not contained in this year's flu vaccine.
Further information can be found on the Centers for Disease Control and Prevention's influenza website.