Influenza Vaccine Patient Education Handout associated with UMHS Clinical Care Guideline

This information is not a tool for self-diagnosis or a substitute for medical treatment. You should speak to your health-care provider or make an appointment to be seen if you have questions or concerns about this information or your medical condition.

Spanish version

When you get a flu shot you are injected in the arm with the influenza (flu) vaccine. The vaccine helps protect adults and children from getting influenza (flu).

A new way to get the flu vaccine is a nasal spray called Flu-Mist. It is a live virus vaccine and can only be used for healthy people ages 5-49.

The flu virus is always present somewhere in the world. In the United States flu outbreaks tend to occur each year between November and March.

The flu causes an upper respiratory infection. The flu often causes fever, muscle aches, headache and dry cough. It can also lead to more severe infections, such as pneumonia. Health problems caused by the flu result in up to 40,000 deaths per year in the U.S. These deaths most often occur in older adults and people with chronic health problems, such as heart disease and severe asthma.

How does the flu vaccine work?
The blueprint for the flu vaccine is changed every year as a result of advice from scientists from the Centers for Disease Control (CDC). They predict which strains of flu virus will most often appear the next winter.

The virus in the flu shot has been inactivated, or "killed." This means you cannot catch the flu from getting a shot. Getting the shot causes part of the killed flu virus to enter your immune system. Your body then reacts by making protective agents to fight the virus. The virus in the nasal spray is weakened but not killed, so it can only be given to healthy people ages 5-49.

How useful are flu vaccines?
Flu vaccines appear to prevent about 70% of people who get the vaccine from getting the flu. Even if you do get the flu, the vaccine helps protect against severe infection. For this reason it is said that the flu vaccine protects against death from the flu more than from flu itself.

The flu vaccine starts working to protect you in 2 to 4 weeks after you get it. It is best to get the vaccine in October of each year. Try to get it no later than November.

What are the side effects?
Eggs are used in making flu vaccine. If you are allergic to eggs, you may have a severe allergic reaction to either the shot or nasal spray. The vaccine should not be taken by anyone who has a history of severe egg allergy.

Some makers of the vaccine suggest not getting a flu shot if you have an allergy to thimerosal. Thimerosal is a preservative used in contact lens solutions and the flu vaccine.

For people who do not have egg or thimerosal allergies, the flu vaccine has rare, minor side effects. The most common side effect is some soreness at the site of the shot. A few people get fever or muscle aches within a few hours of getting the shot. These symptoms may last 1 to 2 days.

Who should get a flu vaccine?
Many groups of people should get the flu shot every year but should not receive the nasal spray: These people are:

• people over the age of 50
• people whose immune systems may be weakened, from things such as HIV, cancer, or an organ transplant
• people with chronic health problems, such as asthma, heart disease, emphysema, and diabetes

Another group of people who should get a flu shot and may qualify for the nasal spray are:

• people working in health care
• school teachers and other workers with close, daily contact with the public.
• Flu shots can be helpful for anyone who is not severely allergic to eggs.