How to Prevent the Flu
Proper vaccination combined with certain good hygiene practices can minimize your risk of getting the flu. Learn more about the yearly flu vacc...

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Proper vaccination combined with certain good hygiene practices can minimize your risk of getting the flu.

Influenza Vaccine

The easiest and most reliable way to avoid contracting the flu is by getting a yearly flu shot. It has been estimated that 70 to 90 percent of all illnesses caused by the flu could be prevented with proper vaccination.

Type A flu viruses are most active in cooler weather, and flu season generally runs from late fall through early spring in temperate climates. Production of the vaccine is timed so it will be widely available before the onset of flu season, roughly in October or November in the Northern Hemisphere.

Because flu viruses are constantly evolving, new flu vaccines must be formulated every year to keep up with the changes. Researchers first identify the three strains that seem most likely to be active in the upcoming flu season. Manufacturers then produce a vaccine with a mix of inactive or weakened strains that match the three active strains as closely as possible. The H1N1 vaccine was developed separately for the 2009 to 2010 flu season, but it will be included in the regular flu vaccine for the 2010 to 2011 season.

When there is a  good match between the vaccine and that year’s actual strains, the vaccine can be 70 to 90 percent effective in preventing illness in people younger than 65. The vaccine’s effectiveness tapers off for those over 65. Even so, it can mitigate the severity of symptoms in elderly patients and prevent life-threatening complications.

Who Should Get Vaccinated

When enough vaccine is available, everyone who is eligible should get vaccinated. When supplies of vaccine are low, it is usually recommended that high-risk groups be vaccinated in order of priority. These groups include:

  • Adults 65 and older
  • Children from 6 months to 5 years old
  • Individuals in nursing homes or chronic-care facilities
  • Persons with diabetes or heart, lung, kidney, liver, blood, or metabolic diseases
  • Pregnant women
  • Health-care workers, teachers, and caregivers
  • Individuals with weakened immune systems
  • Children 18 and under who are on long-term aspirin therapy
  • Morbidly obese people (those who have a body-mass index higher than 30)
  • Family members of any of the above groups

Once a vaccine is administered, it generally takes up to two weeks for the body to build up full immunity. Adults should receive a single dose of vaccine at least a few weeks before the onset of flu season. Children need two doses one month apart to build full immunity. But even if you don’t get your shot before the start of flu season, you can still get vaccinated throughout flu season to minimize your chances of infection.

Serious side effects from the flu vaccine are very rare, and inactive viruses cannot cause the flu. The most common side effect is soreness at the site of the injection. Children may experience mild flu-like symptoms such as a slight fever and body aches.

Nasal Spray Vaccine

An alternative to the flu shot is a nasal spray vaccine (FluMist). The flu shot is made with inactive virus and is appropriate for most people over 6 months of age. The nasal spray, on the other hand, is made with a weakened live virus and is available for healthy individuals from age 2 to 49 who are not pregnant.

Who Should Not Get Vaccinated

While the Center for Disease Control encourages nearly everyone to get flu vaccinations, there are some people would suffer adverse effects from getting vaccinated.


Babies younger than 6 months old do not have fully developed immune systems and should not get vaccinated. Instead, parents and individuals who care for infants should get their shot in order to build a “cocoon” of immunity around the child. Breastfeeding of infants can result in the passage of some protection against the flu from the breastfeeder to the baby.


Like infants, people over the age of 65 are urged not to get certain vaccinations, such as nasal-spray flu vaccinated LAIV (FluMist), due to possibly compromised immune systems. Consult your doctor before considering any vaccinations if you are over the age of 65.

People With Certain Allergies

People who are allergic to eggs or other components of vaccines should not receive the vaccine.

Personal Hygiene

The influenza virus spreads when people inhale the virus on the fine droplets given off when others sneeze, cough, or even just talk. The virus can also spread when you touch an infected surface like a doorknob or light switch and then touch your eyes, nose, or mouth. Apart from getting vaccinated, there are many additional ways to reduce your chances of contracting the flu.

Probably the best thing you can do is wash your hands frequently with soap and water and avoid touching your face with your hands. If soap and water aren’t readily available, an alcohol-based sanitizer can be just as effective. Wash your hands after eating, using the restroom, handling dirty laundry, or cleaning dirty dishes and eating utensils. Clean and disinfect children’s toys regularly. 

If the flu hits your family or community, avoid contact with people who are clearly infected or sick. Avoid large crowds and enclosed spaces. If you are in a high-risk group and you have to go out during a flu epidemic, use a respirator mask (N95 is best) to minimize your chances of inhaling the virus.

If you come down with the flu, cover your mouth with a tissue when coughing or sneezing and throw dirty tissues away immediately. If you don’t have a tissue, cough into your elbow, not your hand. Wash your hands frequently and stay home from work or school until your fever is gone. Avoid other people as much as possible. If you have to go out, wear a mask to protect others.

Written by: the Healthline Editorial Team
Edited by:
Medically Reviewed by: Jennifer Monti, MD, MPH
Published: Aug 25, 2010
Published By: Healthline Networks, Inc.
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