According to the Centers for Disease Control and Prevention, on average 5 to 20 percent of the population in the U.S. gets the flu each year. More than 200,000 people are hospitalized from seasonal flu-related complications, and anywhere from a few thousand to 50,000 people die each year from flu.

The best way to prevent getting the flu, says the CDC, is by getting a seasonal flu vaccination each year. But do the benefits of getting the flu shot far outweigh the risks? Can potential lethal illnesses manifest years later in life, a direct result from getting yearly flu shots?

The truth about getting the flu vaccine is difficult to ascertain, with opinions about its safety differing widely depending on which medical professional you ask.

The flu shot does not give you the flu, most of the time

One thing both proponents and opponents of the flu shot agree on is that there are a few different types of flu vaccines, and sometimes, adverse side effects do occur from the shot.

Currently, there are four types of flu vaccines on the market:

  • A standard flu shot
  • A high-dose flu shot for those 65 and older
  • An intradermal-administered shot for those who are needle-phobic
  • A nasal spray

Contrary to what many people believe, the first three vaccines listed above do not contain the live flu virus. “The vaccine is taken from two of the hundreds of different proteins that compose an influenza virus,” says the Mayo Clinic and Infectious Disease Society of America's Dr. Greg Poland. “Taking merely two surface proteins off the virus does not mean it’s live; there’s no organism there … it’s not possible to cause infection or disease with it … the flu shot does not give you the flu,” adds Poland.

As for the nasal spray, there are conflicting reports on its efficacy.

In June 2016, the CDC recommended against using the flu spray for the 2016-2017 flu season, citing a lack of evidence that it had been effective in the past. However, a few months later, a Canadian study appeared to offer contradicting evidence about the spray's effectiveness. As NPR points out, however, the two findings are not comparing the same thing as one looked at evidence of the vaccine that used three strains of the virus and another looked at a four-strain vaccine.

Does the government conclude that flu shots are 100 percent safe and effective?

No, but close to it. The CDC says the flu vaccines are "among the safest medical products in use."

Adverse side effects have been documented in peer-reviewed medical journals. For example, a study in Human and Experimental Toxicology reported that there were 590 fetal-loss reports per 1 million pregnant women vaccinated (or 1 per 1,695) during the 2009-2010 flu season.

According to most peer-reviewed research, the chances of encountering problems are statistically minimal; however, possible adverse effects from flu vaccine documented in medical literature include:

  • Febrile seizure
  • Narcolepsy
  • Asthma
  • Guillain-Barré syndrome

Humane reasons to get the flu shot

Some medical professionals, such as Dr. Elizabeth Baorto, division director of Pediatric Infectious Disease at Goryeb Children’s Hospital in Morristown, New Jersey, strongly believe that with rare exception — such as someone with an egg allergy — everybody 6 months and older should get a flu shot every year.

“Protecting oneself is an altruistic act. By getting vaccinated, you not only protect yourself, but you protect those around you as well,” says Baorto. “We are fortunate that we have a cheap and effective way of protecting ourselves with the flu vaccine.”

So, is it in your best interest to get the flu vaccine, regardless if a superbug is headed our way?

Poland unequivocally thinks so. “Which risk would you take?” he asks: “One in a million of a side effect or a one in 10,000 risk being hospitalized or dying. Flu-related illnesses cost the U.S. $90 billion a year, or almost one percent of GDP,” adds Poland.

Editor's note: This story was published in 2012 and has been updated with new information.