Influenza Vaccine
En Español (Spanish Version)
For the latest information on influenza vaccination, visit the Centers for Disease Control and Prevention website at
http://www.cdc.gov/flu/other_flu.htm
Influenza
(also called
the flu) is an upper respiratory infection. It is caused by the influenza virus. Flu strains differ from one year to the next. There are two main kinds infecting humans:
You can get the flu when you breathe in droplets from someone infected with the virus. It can also be spread by touching a contaminated surface and then putting your hand to your mouth or nose.
Each year (usually beginning in October), the flu spreads around the world. Anyone can get it, but some are at a higher risk of complications. People at higher risk of complications include:
- Being younger than 5 years old
- Being 65 years old and older
-
Having certain conditions, including:
- Chronic lung condition (eg,
asthma)
- Cardiovascular disease
- Kidney or liver disease
- Neurological, blood, or metabolic condition (eg, diabetes)
-
Having a suppressed immune system (eg,
HIV)
- Being pregnant
-
Being a child or teen who receives long-term aspirin therapy
- Living in nursing homes or other long-term care facilities
- Being American Indian/Alaska Native
-
Being severely
obese
Symptoms include:
- Fever and chills
- Severe muscle aches
- Cough
- Severe fatigue
- Headache
- Decreased appetite, other gastrointestinal symptoms (eg, nausea, vomiting)
- Runny nose, nasal congestion
- Sneezing
-
Watery eyes,
conjunctivitis
- Sore throat
- Swollen lymph nodes in the neck
Treatment may include:
- Bed rest
- Fluids
- Over-the-counter pain relievers
- Decongestants
- Cough suppressants
- Antiviral medicines
There are two types of influenza vaccines:
- Flu shot—trivalent influenza vaccine (TIV)
- Nasal spray (FluMist)—live, attenuated influenza vaccine (LAIV)
The flu shot is approved for use in people older than six months. The shot is made from an inactivated, killed virus. It is given by injection, usually into the arm.
The nasal spray flu vaccine is approved for healthy people aged 2-49 years who are not pregnant. It is made from live, weakened flu viruses. It is sprayed into the nose.
Both vaccines contain three influenza viral strains. The type of strains that the vaccine contains change from year to year based on which viruses are likely to circulate during that flu season.
There is also a high-dose vaccine (
Fluzone) that may be an option for people aged 65 or older.
The Centers for Disease Control and Prevention (CDC) recommend that anyone aged six months and older should get a flu shot.
It takes about two weeks for the vaccination to protect you against the flu. Even if you have been vaccinated, you can still get the flu. If you have symptoms, tell your doctor.
You can get the flu anytime during the year, however, flu season typically lasts from October to May. The best time to get vaccinated is as soon as the vaccine becomes available. Doing so will protect you before the flu comes to your community.
If your child is younger than 9 years old, he may need two doses of the flu vaccine. This may need to be given to help your child build immunity to the virus. Talk to the doctor to find out how many doses are right for your child.
Almost all people who receive the influenza vaccine have no problems. There are certain risks associated with the vaccine. As with any vaccine, there is a small risk of serious problems, including severe allergic reaction.
Adverse effects associated with the flu shot include:
- Soreness, redness, and swelling around the injection site
- Low-grade fever
- Muscle aches
Adverse effects associated with the nasal spray vaccine include:
- Runny nose
- Headache
- Vomiting
- Muscle aches
- Fever
- Sore throat
- Cough
Certain people should talk to their doctor before receiving the influenza vaccine. These include people who:
- Have any severe (life-threatening) allergies (including allergy to eggs)
- Have had a severe reaction to the flu vaccine in the past
- Have had Guillain-Barré syndrome
- Currently are sick
- Have gotten any other vaccines in the last 4 weeks (for nasal spray only)
The following people should not get the
nasal spray:
- People who are aged 50 years and older
- Children aged less than 24 months
- Children aged less than 5 years who have asthma (including wheezing)
- Pregnant women
- People with chronic conditions (eg, heart disease, lung disease, asthma, kidney or liver disease, metabolic disease, blood disorders)
- People with nerve or muscle disorders
- People with weakened immune systems
- People in close contact with others who have a weakened immune system
- Children or teens on long-term aspirin therapy
Good preventive measures include:
- Avoid close contact with people who have respiratory infections.
- Wash your hands often for 15-20 seconds with soap and water, especially when you come in contact with someone who is sick. Rubbing alcohol-based cleaners on your hands is also useful.
- Do not share drinks or personal items.
- Cover your nose and mouth with a tissue when coughing or sneezing.
- Do not put your hands near your eyes, mouth, or nose.
In the event of an outbreak, vaccinating as many susceptible people as possible, especially those in priority groups, is the primary focus. In addition, the use of antiviral medications (eg,
oseltamivir
,
zanamivir) can reduce the duration of the illness when given within two days of onset. Finally, people who are infected should be isolated as much as possible.
WHERE CAN I GET MORE INFORMATION?
National Immunization Program
Centers for Disease Control and Prevention
Public Health Agency of Canada
Vaccines
United States Food and Drug Administration
Asthma information for patients and parents of patients. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/H1N1flu/asthma.htm. Updated September 15, 2009. Accessed September 15, 2009.
Baker CJ, Pickerling LK, Chilton L, et al; Advisory Committee on Immunization Practices. Recommended adult immunization schedule: United States, 2011. Ann Intern Med. 2011;154(3):168-173.
Centers for Disease Control and Prevention. Recommended immunization schedules for persons aged 0-18 years —United States, 2011. MMWR. 2011;60(5).
Vaccines and immunizations. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/nip. Accessed February 6, 2007.
10/15/2007 DynaMed Systematic Literature Surveillance
http://www.ebscohost.com/dynamed/what.php: Nichol KL, Nordin JD, Nelson DB, Mullooly JP, Hak E. Effectiveness of influenza vaccine in the community-dwelling elderly.
N Engl J Med
. 2007;357:1373-1381.
8/10/2010 DynaMed's Systematic Literature Surveillance
DynaMed's Systematic Literature Surveillance: Fiore A, Uyeki T, Broder K, et al. Prevention and control of influenza with vaccines
recommendations of the Advisory Committee on Immunization Practices (ACIP), 2010.
MMWR. 2010;59:1-62.
Last Reviewed November 2011