The Flu Vaccine

Flu shot (vaccine)

The best way to prevent or lessen the severity of the flu is to get a flu shot each fall.

You cannot get the flu from a seasonal vaccine. Over the years, hundreds of millions of Americans have received flu shots. If you’re worried about shots, you may take the nasal spray.

Types of Flu Vaccines

There are 2 types of flu vaccines:

  • The “flu shot” is an inactivated (or killed) vaccine given with a needle, usually in the arm.
  • The nasal flu spray vaccine (also referred to as LAIV for “Live Attenuated Influenza Vaccine”) is an attenuated (or weakened) vaccine taken via a spray in the nose.

Scientists make a different flu vaccine every year because the strains of influenza viruses change from year to year. Nine to ten months before the flu season begins, a new vaccine is made from inactivated (killed) influenza viruses. Because the viruses have been killed, they cannot cause infection. The flu vaccine preparation is based on the strains of the flu viruses that are in circulation at the time. It includes those influenza Type A and Type B viruses expected to circulate the following winter.

Sometimes a new strain appears after the vaccine has been made and distributed to doctors’ offices and clinics. As a result, you still may get infected even if you get a flu shot.


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