Each fall, medical professionals encourage us to get flu shots in order to lessen our chances of coming down with influenza. For some of us, the flu vaccine can provide protection, or decrease the severity of the illness if we do get sick.

But the flu shot isn't necessarily the right choice for everyone.

Pros of getting a flu shot

According to the Centers for Disease Control and Prevention, the single best way to prevent the flu is to get vaccinated each year. About two weeks after receiving a flu shot, antibodies develop that protect against influenza virus infection.

The flu vaccine, which contains three influenza viruses, changes annually, based on scientists' estimates about which types and strains of viruses will be prevalent that year.

Annual flu shots are strongly recommended for two groups:

People at high risk for complications from the flu, including:

  • Children ages six months to five years;
  • Pregnant women;
  • People ages 65 and older;
  • People with certain chronic medical conditions;
  • People living in nursing homes or other long-term facilities.

People who live with or care for those at high risk for complications from flu, including:

  • Household contacts of persons at high risk for complications from the flu;
  • Household contacts and caregivers of children less than six months of age;
  • Healthcare workers.

Cons of the flu vaccine

You cannot get the flu from a flu shot, due to the viruses being inactive. But you may experience unpleasant side effects, including soreness or redness at the site of the injection, aches, or a low-grade fever.

Some medical professionals believe that the immune system is strengthened by having a chance to fight off viruses. So getting an annual flu shot can weaken the immune system's natural defense mechanisms.

Some groups of people should not receive a flu shot without first consulting a physician, including:

  • People with a severe allergy to chicken eggs;
  • People who have experience a previous severe reaction to an influenza shot;
  • People who developed Guillain-Barré Syndrome (GBS) within six weeks of getting a previous influenza vaccine;
  • Children younger than six months;
  • People with a moderate or severe illness with a fever should wait to get vaccinated until their symptoms lessen.

Other options to prevent influenza

The nasal-spray flu vaccine, also know as live attenuated influenza vaccine (LAIV), was licensed in 2003. The difference between LAIV and the flu shot is that LAIV contains weakened live (active) influenza viruses, versus the killed (inactive) viruses in the flu vaccine.

LAIV is approved for use on healthy people between ages two and 49, with the exception of pregnant women.

A two-year study of children between 15 and 84 months of age showed that the nasal-spray vaccine was about 92 percent effective in preventing the flu.

Although the nasal-spray vaccine was shown to be effective in young children, the vaccine is not recommended for children younger than two.

Don't like needles?

“Fluzone Intradermal®” was licensed by the FDA for use in the U.S. starting with the 2011-2012 flu season. Approved for adults, ages 18-64,  the shot is injected into the skin instead of the muscle. That means a much smaller needle can be used to administer the vaccine.

Check with your doctor for availability.