What is the flu vaccine? — The flu vaccine is a treatment that can keep you from getting sick with the flu. The flu is an infection that can cause fever, cough, body aches, and other symptoms. There are different forms of the flu, including the “seasonal” flu, the 2009-2010 pandemic H1N1 flu (also called the “swine” flu), and the bird flu (also called the “avian” flu). All forms of the flu are caused by viruses. The medical term for the flu is “influenza.” Vaccines are also called “vaccinations” or “immunizations.”
This article is about the flu vaccine that can protect you from the seasonal flu. The flu vaccines that are available now do not protect against bird flu.
Who should get the flu vaccine and when? — All people age 6 months or older should get the flu vaccine every year. The vaccine is especially important for certain people at high risk (table 1).
The best time of year to get the flu vaccine is before the winter season begins. In the United States, it’s best to get the vaccine by October. In southern countries, where winter happens in July and August, it’s best to get the vaccine by May. No matter where you live, do your best to get the vaccine soon after it becomes available in your area. Depending on how many doses they have had in the past, children ages 6 months through 8 years might need 2 doses of the vaccine for it to work best.
Why should I get the flu vaccine? — Getting vaccinated can help keep you from getting sick. Plus, being vaccinated can help protect those around you from getting sick. If you have been vaccinated but get the flu, the vaccine can also keep you from getting severely ill or even dying.
Some years the flu vaccine is more effective than others. That’s because the people developing the vaccines can’t predict exactly how the flu virus is going to change year to year.
Some people think the flu vaccine doesn’t work, because they have known people who got the vaccine and got the flu anyway. But that does not mean the vaccine does not work. Many people who get sick after getting the flu vaccine do not actually have the flu; they have a cold caused by a virus unrelated to the flu virus, so the flu vaccine can’t help with that that.
Even in years when the vaccine is less effective, it still helps prevent some cases of the flu and also helps to prevent serious illness and outbreaks of the flu.
Are there different forms of the flu vaccine? — Yes. The flu vaccine comes in different forms, including:
●A shot that goes into muscle (usually in the upper part of the arm)
●A shot that goes under the skin
●A nasal spray
If you are age 65 or older, you should only get the vaccine that goes into muscle. Ask about getting the high-dose version of this vaccine, if it is available. In older people, the high-dose version works a little better than the standard-dose version, though both are effective.
For healthy children ages 2 to 8 years, experts recommend the nasal spray instead of the shot, if it is available right away. If not, the shot works well, too.
What side effects does the flu vaccine cause? — Often the vaccine causes no side effects. When it does cause side effects, it can cause:
●Redness, mild swelling, or soreness where you got the shot (if you got a shot)
●A mild fever
●A mild rash
●Headache or body aches
Vaccines also sometimes cause more serious side effects, such as severe allergic reactions. But serious side effects are rare.
Does the flu vaccine cause the flu? — No, the flu vaccine does not cause the flu. People sometimes feel sick after getting the vaccine, but this is often because they were already starting to get sick with the flu or another virus before they had the vaccine.
Does the flu vaccine cause autism? — No. After doing many careful studies, scientists have not found any link between vaccines and autism. Many years ago, a study reported a link between autism and vaccines. But that study turned out to be false. It has been withdrawn.
What if I am pregnant? — If you are pregnant, it is very important to get the flu vaccine. In pregnant women, flu symptoms can get worse quickly and be dangerous. The flu can even cause trouble breathing or lead to death of the woman or her baby. That is why it is so important to get the flu vaccine if you are or will be pregnant during flu season.
What if I have an egg allergy? — If you have an egg allergy, you should still get the flu vaccine. People with serious egg allergies sometimes have a bad reaction to some versions of the flu vaccine. But people with mild allergies can often take egg-made vaccines. Plus, there are now egg-free versions of the flu vaccine, which can be used in adults 18 to 49 years of age. If you have an egg allergy, remember to tell your doctor or nurse. That way, he or she can choose the safest flu vaccine for you and keep an eye on you after you get the vaccine to make sure that you do not have a bad reaction.
What else can I do to prevent the flu? — In addition to getting the flu vaccine every year, you can:
●Wash your hands often with soap and water, or use alcohol hand rubs
●Stay away from people you know are sick
If you are exposed to the flu, antiviral medicines can help protect you from the flu, but those medicines are not appropriate for everyone. Also, antiviral medicines work only if you start them very soon after being exposed or as soon as you show symptoms.
To protect others, you should also:
●Stay home if you get the flu. Do not go to work or school until your fever has been gone for at least 24 hours, without taking fever-reducing medicine, such as Tylenol. If you work in a healthcare setting taking care of patients, you might need to stay home longer if you are still coughing.
●Cover your mouth and nose with the inside of your elbow when you cough or sneeze.