An annual flu vaccine is the best way to reduce your chances of getting the seasonal flu and spreading it to others. CDC recommends that everyone 6 months of age and older receive an annual flu vaccine.
Each year, the Center for Disease Control works with the U.S. Food and Drug Administration and other partners to ensure the highest safety standards for flu vaccines.
Flu shots are made by using killed flu viruses (for inactivated vaccines), or without flu virus at all (for the recombinant vaccine).
Flu vaccines cause antibodies to develop in the body about two weeks after vaccination. These antibodies provide protection against infection with the viruses that are in the vaccine.
Since the flu virus changes, new vaccines need to be made and administered every year. This is why you need to get a new flu vaccine every year!