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Flu in Adults (cont.)

Prevention of Flu in Adults

Personal hygiene

  • Wash your hands frequently with soap and water.
  • Avoid touching your eyes, nose, or mouth before washing your hands.
  • Avoid close contact with people who are ill.
  • Do not share clothes or other personal items with another person during a flu outbreak.
  • Those infected with influenza should stay at home for 24 hours after fevers have resolved.


The best means of preventing the flu is getting an influenza vaccination. The U.S. Centers for Disease Control and Prevention (CDC) recommends an annual flu vaccine for everyone 6 months of age and older. Two types of vaccines are available. One is the injectable vaccine made from inactivated virus, known as the flu shot. The flu shot contains only killed influenza viruses A and B. The other is a live attenuated, or weakened, virus that is squirted into the nose. This is called intranasal vaccine or nasal spray vaccine. The intranasal form is available for certain people who may prefer it to a shot, and it is approved for people from 2 through 49 years of age. It is not recommended for people who are immunosuppressed or have other conditions (see below for a list). In addition, there are variations such as a high-dose shot formulation for people over 65 years of age and an intradermal (into the skin) version for ages 18-65 that uses a tiny needle. A complete listing of flu vaccines that are currently available can be found at

The influenza vaccine is given every year prior to flu season. Immunity to the flu virus develops after about two weeks. The CDC recommends that vaccine be given starting as soon as it becomes available each fall.

In the 2009-2010 influenza season, there were two distinct vaccines, one for the seasonal strain and one for the pandemic H1N1 strain. For the 2011-2012 season, the H1N1 strain was included along with other strains in the regular seasonal flu shot.

The composition of the flu vaccine for the 2014-2015 season is the same as for the 2013-2014 season and contains two strains of influenza A (and H1N1 strain and an H3N2 strain) and one strain of influenza B viruses.

There is also available a vaccine that contains four viral strains called a quadravalent vaccine. This contains the three strains above as well as a second influenza B strain. This vaccine may protect against a second strain of influenza B that often circulates through the population.

Currently, the CDC does not recommend one type of flu vaccine (nasal vs. shot or trivalent (three strains) vs. quadravalent (four strains) over another, except that the nasal spray vaccine is preferred for healthy children ages 2-8 if it is immediately available.

  • Because of substantial vaccine distribution delays during previous influenza seasons and the possibility of similar delays in the future, it is recommended that anyone at high risk for complications from the flu get a flu shot as early as September. This same group of people can even get the vaccine in December and throughout the flu season if they were unable to be vaccinated earlier.
  • The vaccine is effective in about 70%-90% of those who get the shot, especially in older people. Not only does it decrease the risk of getting flu infection, but it can also decrease the number of visits to a doctor's office, hospitalizations, and risk of death from the flu virus. However, in some years the vaccine is less effective because the circulating flu virus has genetically changed from the ones anticipated and included in the vaccine. The 2014-15 flu vaccine was only 23% effective due to this change in the virus that season.
  • Who should get the flu vaccine?
    • Vaccination for the flu each year is recommended for all people over 6 months of age. Those at higher risk should be especially sure to get vaccinated. These include the following:
    • Anyone older than 50 years of age
    • A person of any age with chronic diseases of the heart, lungs, or kidneys
    • People with obesity or diabetes
    • Those who are HIV positive or have AIDS
    • Women who are more than 14 weeks pregnant during the flu season (Women who are pregnant at any stage of their pregnancy and have a risk of complications from the flu should get the vaccine irrespective of how far they are into the pregnancy. Breastfeeding women can also get the flu shot without worry about harm to the baby.)
    • Residents of nursing homes and other facilities of long-term care
    • Children older than 6 months of age who have chronic heart or lung conditions, including asthma
    • Children older than 6 months of age who need regular medical care or had to be in a hospital because of metabolic diseases (such as diabetes), chronic kidney disease, or weakened immune systems (including immune system problems caused by medicine or by infection with human immunodeficiency virus [HIV/AIDS])
    • Children and teenagers (6 months to 18 years of age) who are on long-term aspirin therapy and therefore could develop Reye's syndrome after a flu illness
    • Health-care professionals and volunteers who work with high-risk patients, including employees of nursing homes and chronic-care facilities
    • Household members (including children) of people in high-risk groups
    • Students or others living in institutional settings (for example, those who reside in dormitories or camps where close contact is likely)
    • Anyone interested in reducing the risk of getting the flu
    • The intranasal or live vaccine (FluMist and others) is an alternative to the flu shot in people who are healthy, 2-49 years of age, and not pregnant. Exceptions are health-care professionals who care for severely immunosuppressed patients or people caring for children younger than 6 months of age, children age 2 through 4 with asthma, and children age 2-17 on long-term aspirin treatment.
    • People who are allergic to eggs or who have had Guillain-Barré syndrome (paralysis) within six weeks of a prior vaccination should check with their doctor before getting an influenza vaccine.
  • Updates on the seasonal flu vaccine are available on the CDC web site, influenza (flu) (
Medically Reviewed by a Doctor on 4/2/2015
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