Before flu season begins, scientists prepare a new influenza vaccine made from inactivated (killed) flu viruses, which cannot cause infection. The preparation is based on the flu viruses that are currently in circulation and on viruses that are expected to circulate the following winter. The influenza vaccine is a yearly vaccination because the viruses that cause the disease change every year.
The main way to keep from getting the flu is to get a yearly influenza vaccine. You can get the vaccine at:
- Your doctor's office
- A local clinic
- Work (in many communities)
It is important to note that you must get the influenza vaccine every year because the viruses on which it is based change every year.
Scientists make a different influenza vaccine every year because the strains of flu viruses change from year to year. Nine to ten months before the flu season begins, scientists prepare a new influenza vaccine made from inactivated (killed) flu viruses. Because the viruses are killed, they cannot cause infection. The influenza vaccine preparation is based on the flu viruses that are in circulation at the time and on the viruses that are expected to circulate the following winter.
It is important to note that an unpredicted new strain of the flu virus may appear after the influenza vaccine has been made and distributed to doctors' offices and clinics. This means that even if you do get the influenza vaccine, you still may get infected. However, if this happens, the disease is usually milder because the influenza vaccine will still give you some protection.
(Click Flu Virus for more information about flu viruses.)