Getting Your FLU Shot

By Cynthia Napier Rosenberg, M.D., SeniorMedical Director, UPMC Health Plan

There are times when we get sick even if we take good care of ourselves. Not all illnesses can be prevented. But there are many things that we can do to help protect ourselves from becoming sick. One of the easiest and best things we can do for ourselves is to make sure that we get our annual flu shot.

What is “the flu shot”?

The flu shot is a vaccination that protects us against the influenza virus. There are three main types of influenza virus (A, B and C) and many different strains of influenza A (the type that causes the most severe illness in humans). Since the genetic composition of the strains can change over time, we need to get a flu shot every year.

Each year scientists study the types of influenza currently affecting humans to determine which are the most likely to cause illness in the following year. Each year three strains are selected. The selected viruses for the upcoming flu shot are grown in eggs and then inactivated (killed). Each year, the flu shot contains killed virus for these three strains to protect us from becoming infected with influenza.

Can I get the flu from the flu shot?

No. Since the viruses are killed, it is not possible to get influenza from a flu shot.

Can I get the flu even if I have had the flu shot?

It takes about two weeks after you get the flu shot for your body to develop immunity against the influenza viruses in the vaccine. If you are exposed to the flu before the two-week period has passed, you may still come down with the illness.

In addition, many people commonly refer to a wide variety of illnesses as “the flu.” Other viruses can cause flu-like symptoms. Gastrointestinal symptoms (nausea, vomiting, diarrhea) are not associated with influenza.

Finally, no vaccine is 100 percent effective. Some people may still contract influenza even if they are vaccinated. However, in those cases, the flu vaccine can still provide some protection and help to prevent the illness from being as severe as it might otherwise have been.

What are the side effects of the flu shot?

It is possible to have a reaction such as low-grade fever, aches and redness or soreness at the injection site. These problems usually last only one or two days. Occasionally, severe allergic reactions can occur. These reactions are more likely to occur in people who have a severe allergy to eggs, since the influenza viruses used in the vaccine are grown in eggs.

If you know that you have an allergy to eggs, if you have had a severe reaction to eggs in the past, or if you have ever had a severe reaction to a flu shot, you should not get a flu shot unless you first talk to your doctor. Your doctor can help you to decide whether or not it is safe for you to get the flu shot.

Who should get a flu shot?

Although anyone can get the flu shot to protect against coming down with influenza, the vaccine is recommended for the following groups:

• Children over six months of age up to their 19th birthday
• Pregnant women
• Anyone 50 years of age and older
• Anyone with a chronic medical condition such as diabetes, asthma, heart disease, chronic lung disease or kidney disease
• Children and adolescents who take aspirin regularly Anyone who lives in an institutional setting such as a nursing home
• Anyone who lives with or cares for others who are at high risk for getting complications of the flu (such as health care workers and caregivers)

When should I get my flu shot?

The best time to get the flu shot is early in the fall before the flu season begins. However, since the flu season usually lasts until March, you can get a flu shot even after the flu season has begun (usually some time in November).

I don’t like shots. Can I get the nasal spray flu vaccine?

The nasal spray vaccine is made with a live but weakened virus. It is approved only for people between the ages of 2 and 49 who are not pregnant and who do not have any underlying medical conditions.

Cynthia Napier Rosenberg, M.D., is Senior Medical Director for UPMC Health Plan. For more information, visit upmchealthplan.com.

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