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)
- Supermarkets
- Drugstores.
It is important to note that you must get flu shots every year because the injections change every year.
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.)
Until recently, you could get flu shots only as an injection. However, in 2003, the U.S. Food and Drug Administration (FDA) approved a nasal spray called FluMist®, which you can get from your healthcare provider. The FDA approved it for use in healthy people who are 5 to 49 years of age.
You should not use FluMist if you:
- Have certain lung conditions, including asthma, or heart conditions
- Have metabolic disorders, such as diabetes or kidney dysfunction
- Have an immunodeficiency disease or you are on immunosuppressive treatment
- Have had Guillain-Barré syndrome
- Are pregnant
- Have a history of allergy or hypersensitivity to any of the parts of FluMist or to eggs
- Are a child or teenager who regularly takes aspirin or products containing aspirin.
When Should I Get Flu Shots?
Your immune system takes time to respond to flu shots. Therefore, you should get vaccinated six to eight weeks before flu season begins in November to prevent infection or to reduce the severity of
the flu if you do get it. However, flu season usually lasts until March, so it is not too late to get shots after the season has begun.
Flu shots by themselves cannot cause the flu, but you could become exposed to the virus by someone else and get infected soon after you are vaccinated.
Approximately 5 to 10 percent of people who get flu shots will have mild side effects for about a day after vaccination. The most common side effect in children and adults is soreness at the site of the vaccination. Other side effects, especially in children who previously have not been exposed to the
flu virus, include:
These side effects may begin 6 to 12 hours after vaccination and may last for up to 2 days.
Viruses for producing flu shots are grown in chicken eggs and then killed with a chemical so that they can no longer cause an infection. As a result, flu shots may contain some egg protein, which can cause an allergic reaction. If you are allergic to eggs or have ever had a serious allergic reaction to flu shots, the Centers for Disease Control and Prevention (CDC) recommends that you consult with your healthcare provider before getting vaccinated.
Who Should Get Flu Shots?
People who are in any of the following groups, or who live in a household with someone who is, should get a flu shot:
- You are 50 years of age or older
- You have chronic diseases of your heart, lungs, or kidneys
- You have diabetes
- Your immune system does not function properly
- You have a severe form of anemia
- You will be more than three months pregnant during the flu season
- You live in a nursing home or other chronic-care housing facility
- You are in close contact with children 23 months of age or younger.
The CDC recommends that children 6 to 23 months of age get flu shots. Children and teenagers (2 to 18 years of age) should get shots if they are taking long-term aspirin treatment, as they may be at risk of developing Reye's syndrome following a flu infection. Children should also get shots if they live in a household with someone in the previously mentioned groups. Healthcare providers and volunteers should get flu shots if they work with people in any of these groups.
