Before the flu season begins, scientists prepare new flu shots made from inactive flu viruses, which cannot cause infection. The preparation is based on the viruses that are in circulation at the time and on viruses that are expected to circulate the following winter. You must get flu shots every year, because the vaccination changes yearly as the viruses change.
Flu Shots: An Introduction
The main way to keep from getting the flu is to get yearly flu shots. You can get these shots at:
- Your doctor's office
- A local clinic
- Your workplace (in many communities)
It is important to note that you must get flu shots every year because the injections change every year.
How the Shots Are Made
Scientists make different flu shots every year because the strains of flu viruses change from year to year. Nine to ten months before the flu season begins, scientists will prepare new shots made from inactivated (killed) flu viruses. Because the viruses are killed, they cannot cause infection. The flu shot preparation is based on the 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 shots have been made and distributed to doctors' offices and clinics. This means that even if you get the flu shot, you still may get infected. However, if you do get infected, the disease is usually milder because the shots will still give you some protection.
(Click Flu Virus for more information about these viruses.)