Krisha McCoy, MS
the flu) is an upper respiratory infection. It is caused by a strain of the influenza virus. There are many types of influenza viruses but there are two main kinds that infect humans:
Each year (usually beginning in October), the flu spreads around the world. 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, then putting your hand to your mouth or nose. For most, the flu will cause fever, aches, fatigue, coughing, congestion, loss of appetite, and sore throat. However, some people are more vulnerable to more severe complications which may require hospitalization. Risk factors for severe complications include:
The flu shot is made from an inactivated, killed virus. There are 3 types of flu shots available:
There is also a nasal spray (FluMist) made from live, weakened flu viruses. The nasal spray is available for healthy people aged 2-49 years who are not pregnant. It is the preferred vaccine for healthy children who are 2-8 years of age.
The flu shots and nasal spray contain several influenza viral strains. The type of strains that the vaccine contains change from year to year. The strains are based on which viruses are likely to circulate during that flu season.
The Centers for Disease Control and Prevention (CDC) recommend that anyone aged 6 months and older should get a flu shot. Children 6 months to 8 years of age will need 2 doses of the vaccine. This will help your child build immunity to the virus.
It takes about 2 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. But, flu season typically lasts from October to May. The best time to get vaccinated is as soon as the vaccine is available. This will protect you before the flu comes to your community.
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.
Side effects associated with the flu shot include:
Side effects associated with the nasal spray vaccine include:
Certain people should talk to their doctor before receiving the influenza vaccine. These include people who:
The following people should not get the
Good preventive measures include:
In the event of an outbreak, the primary focus is to vaccinate as many at risk people as possible, especially those in high priority groups. The use of antiviral medications can reduce the length 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?
United States Department of Health and Human Services
Vaccines & Immunizations
Centers for Disease Control and Prevention
Public Health Agency of Canada
Vaccines, Blood & Biologics
United States Food and Drug Administration
Fluzone high-dose seasonal influenza vaccine. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/flu/protect/vaccine/qa_fluzone.htm. Updated September 3, 2015. Accessed August 10, 2015.
Influenza in adults. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed. Updated June 17, 2015. Accessed August 10, 2015.
Influenza in children. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed. Updated July 7, 2015. Accessed August 10, 2015.
Influenza vaccine in adults. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed. Updated August 3, 2015. Accessed August 10, 2015.
Influenza vaccine in children. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed. Updated November 21, 2014. Accessed August 10, 2015.
Key facts about seasonal flu vaccine. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/flu/protect/keyfacts.htm. Updated October 22, 2014. Accessed August 10, 2015.
People at high risk of developing flu-related complications. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/flu/about/disease/high_risk.htm. Updated January 8, 2015. Accessed August 10, 2015.
10/15/2007 DynaMed Systematic Literature Surveillance
http://www.ebscohost.com/dynamed: 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(14):1373-1381.
3/5/2012 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed: FDA approves first quadrivalent vaccine to prevent seasonal influenza. US Food and Drug Administration website. Available at:
http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm294057.htm. Updated March 15, 2012. Accessed August 10, 2015.
8/10/2015 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed: Grohskopf LA, Sokolow LZ, Olsen SJ, et al. Prevention and control of influenza with vaccines: Recommendations of the Advisory Committee on immunization practices, United States, 2015-16 influenza season. MMWR Morb Mortal Wkly Rep. 2015;64(30):818-825.
Last reviewed August 2015 by David Horn, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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