What You Need to Know About Flu Shots
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.
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:
- Sore muscles.
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.