How the Flu Works

Who Should Get a Flu Shot?

Studies show anywhere from a 25 percent to a 50 percent decrease in mortality and hospitalization rates for heart patients who get the flu vaccine.
Photo courtesy CDC


­ Anyone in a high-risk group should be vacc­inated at the beginning of every flu season. The CDC recommends that all children ages 6 to 23 months get vaccinated. Very young children are more likely to be hospitalized with the flu, and to die from it, than older children and adults. Because infants under 6 months are too young to take the vaccine safely, all people around them (family members and child care workers) should be vaccinated, as well.


Older adults (over age 65) should also be vaccinated, as well as anyone with a chronic health condition like asthma or diabetes. Plus, the CDC recommends that pregnant women and people who work in the healthcare industry be vaccinated.

Other people who shouldn't receive the flu shot are:

  • People who have had a severe reaction to the flu shot in the past
  • Anyone who developed Guillain-Barré Syndrome, a rare nerve disease, within six weeks of a previous flu shot
  • Infants under 6 months of age
  • Anyone who is running a fever
  • Anyone who is allergic to chicken eggs, because the flu vaccine is grown in eggs

Severe side effects are rare, but many people complain of mild flu-like symptoms, including low-grade fever, muscle aches and tiredness. The side effects usually begin within a few hours after getting the flu shot and can last for about two days.

To find out more about the flu, other diseases and related topics, check out the links below.

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