What are some ingredients in the flu shot?


Quick Answer

Flu shots contain the surface proteins or antigens of current influenza strains, according to the Centers for Disease Control and Prevention. The immune system responds to these antigens by developing antibodies, which protect against the virus. The vaccine may also contain aluminum salts, which further stimulate the body's immune response.

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Full Answer

In addition, flu shots generally include suspending fluids such as sterile water or saline as well as small amounts of additives leftover from the production process, notes the CDC. These additives include antibiotics and formaldehyde, both of which serve to prevent unwanted viral or bacterial growth in the vaccine. In addition, some manufacturers add the preservative thimerosal to multidose vaccine vials to prevent bacterial contamination.

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