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Flu: Prevention

Flu: Prevention

Having the flu is miserable. The flu’s common symptoms of fever, body aches, chills, and fatigue make getting out of bed nearly impossible. And the flu not only affects your body, but it also means time off work (and pay) as well as cancelled plans. Simply put, the flu is no fun.

However, proper vaccination combined with certain good hygiene practices can minimize your risk of contracting this unpleasant virus.

Influenza Vaccine

The easiest and most reliable way to avoid contracting the flu is by getting a yearly flu shot.  

According to the Centers for Disease Control and Prevention (CDC), flu shots are recommended for most individuals six months of age and over. While the success rate of prevention varies year to year, recent studies (within the past 10 years) have found the flu vaccine to be between 60 and 90 percent effective.

Flu season generally runs from late fall through early spring in temperate climates, as Type A flu viruses are most active in cooler weather. Production of the vaccine is timed so it will be widely available before the onset of flu season, which generally occurs 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.

Once a vaccine is administered, it generally takes up to two weeks for the body to build up full immunity. For best results, adults should receive a single dose of vaccine at least a few weeks before the onset of flu season; children six months to eight years of age need two doses one month apart to build full immunity. However, 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 flu vaccines are very rare, and the vaccines cannot cause the flu. The most common side effect is soreness at the site of the injection. Some may experience mild flu-like symptoms, such as a slight fever and body aches. However, any side effects should last only a few days.

Who Should Get Vaccinated?

When enough vaccine is available, everyone who is eligible should be vaccinated. When supplies of vaccine are low, is the CDC recommends that higher-risk groups be given first priority. These groups include:

  • adults 50 and older
  • children from six months to five years old
  • individuals in nursing homes or chronic-care facilities
  • persons with diabetes or heart, lung, kidney, liver, blood, or metabolic diseases
  • pregnant women
  • healthcare 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 40)
  • American Indians or Alaska natives
  • family members of any of the above groups

The Food and Drug Administration (FDA) has recently approved a flu shot (Fluzone Intradermal) for those ages 18 to 64 that is injected into a person’s skin instead of the muscle. What makes this version attractive is that the needle used to administer the vaccine is 90 percent smaller than the typical flu shot needle. Those afraid of needles should ask their doctor about this version, which has been shown to be just as effective at protecting against the flu.

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 six 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 two to 49 who are not pregnant. According to the CDC, studies on the nasal spray have found it to be similarly effective to the flu shot in preventing flu.

However, the nasal spray is not for everyone and can cause serious side effects in certain individuals, especially those with chronic health conditions such as asthma. Talk to your doctor before receiving this vaccine type to make sure you qualify. Pregnant women should not receive the nasal spray vaccine. 

Fluzone High-Dose Vaccine

According to the CDC, those 65 and over account for 90 percent of flu-related deaths each year.

The FDA recently approved Fluzone High-Dose, a high-dose flu vaccine for those 65 and over. Fluzone High-Dose contains four times the amount of antigens as a regular flu shot (Fluzone). Antigens are the part of the flu shot that stimulate the body’s immune system to create antibodies, which combat the flu virus.

When there is a good match between the vaccine and that year’s actual strains, the normal dose vaccine can be highly effective in preventing illness in people younger than 65. However, this vaccine’s effectiveness tapers off for those over 65. This is because the immune system response weakens with age. Therefore, Fluzone High-Dose may help to strengthen this immune response.

Studies have not yet proven the effectiveness of Fluzone High-Dose in preventing flu in those 65 or older. However, according to the CDC, a study comparing its results to the normal dose vaccine should be finished by 2014 or 2015.

Nevertheless, the flu vaccine (whether normal or high-dose) can mitigate the severity of symptoms in elderly patients and prevent life-threatening complications. 

Who Should Not Get Vaccinated?

While the CDC encourages nearly everyone to get flu vaccinations, the following individuals may suffer adverse effects from flu vaccination.


Babies younger than six 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 mother to the baby.

Older Adults

Like infants, people over the age of 50 are urged not to get certain vaccination types, 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 50.

People with Certain Allergies

People who are severely allergic to eggs or other components of vaccines, such as mercury, should not receive the vaccine. Those who are mildly allergic may qualify, however. It is important to talk to your doctor before receiving the vaccine if you have any type of egg or mercury allergy.

If you have ever had Guillain-Barré syndrome (GBS)—a rare side effect of temporary paralysis that occurs after receiving the flu vaccine—talk to your doctor before receiving a flu vaccination. Some individuals at high risk for flu complications and who have had GBS may still be eligible for the vaccine.

People with Fever on the Day of Vaccination

If you have a fever on the day you are scheduled to be vaccinated, cancel the appointment and wait until the fever subsides to receive your vaccination.

Personal and Home Hygiene

The influenza virus spreads when people inhale virus via fine droplets given off when others sneeze, cough, or even 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 (at least 15 seconds) and avoid touching your face with your hands. This is especially important for nail-biters to remember.  

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 countertops, desk surfaces, bathroom and kitchen floors, cutting boards, and children’s toys regularly. These are all places germs like to congregate. Frequently wash dishcloths and towels, and microwave your dish sponges for at least one minute to kill germs.

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 must venture to the store, movie theater, or other public place during peak flu season, consider carrying disinfecting wipes in your purse or briefcase. Use these to wipe down potentially germy surfaces, like grocery cart handles or armrests, for example.

If you are in a high-risk group and you have to go out during a flu epidemic, use a mask, such as an N95 respiratory mask, 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.

Content licensed from:

Written by: the Healthline Editorial Team
Medically reviewed on: Jul 23, 2014: George Krucik, MD, MBA

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
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