Can the Flu Shot Really Save Your Life?

The flu can be dangerous. Learn why getting vaccinated is the best way to protect yourself and your family.

We’ve all heard the advice to get the flu shot each fall. But is it really that important to do?

The short answer: yes.

The flu can be dangerous—even deadly. As of May 4, 2019, as many as 61,200 people died from the flu or flu-related complications during the 2018-2019 flu season, including at least 106 children.

The CDC also reports that between 531,000 and 647,000 people were admitted to the hospital due to the seasonal virus. The flu prompted another 17.3 to 20.1 million people to see their doctor for medical attention.

Although flu season—which typically starts in October and ends in May—was not as severe in 2018-2019 as it's been in years past, it was the longest flu season in a decade, partly because two types of flu viruses surfaced at different times.

Early on, the dominant strain circulating across the United States was the influenza A strain known as H1N1, but a more severe strain of influenza A, H3N2, accounted for more than half of new flu cases late in the flu season. The CDC pointed out that the 2018-2019 seasonal flu vaccine was a good match for these viruses, offering 47 percent protection against all circulating strains. So, those who received this vaccine may have cut their odds of acquiring a severe case of the flu by nearly half.

In comparison, the 2017-2018 flu shot offered just 25 percent effectiveness against H3N2—the predominant strain of flu that season. According to the CDC, 2017 was the deadliest flu season in more than 40 years. From the fall of 2017 to the spring of 2018, the flu claimed the lives of nearly 80,000 people, including 183 children. But it’s possible that up to 600 children actually died from the flu, since pediatric deaths are often underreported. Meanwhile, it’s estimated that roughly 960,000 Americans were hospitalized due to the virus.

Why was 2017 so bad for flu?
Experts say 2017 was such a challenging year due in part to the fact that fewer people rolled up their sleeves and got the flu shot. Just 37.1 percent of adults received the vaccine—a 6.2 percent drop from the year before. The severe H3N2 strain was also dominant, which likely played a role.

These sobering statistics may have served as a wake-up call, prompting more Americans to get the flu shot in 2018. The CDC revealed that by mid-November 2018, more Americans had gotten a flu shot than by the same time the year before. Roughly 46 percent of children and 45 percent of adults had gotten a flu shot—an increase of more than 6 percent for both age groups.

The flu vaccine remains the most effective way to prevent the flu. In a typical year, the effectiveness is around 40 to 60 percent.

Pamela Good, RN, Director of Infection Prevention at Plantation General Hospital in Florida, explains why the flu shot is so important for flu prevention.

What is the flu vaccine?
Although the precise formulations of the vaccine change every year, the basic foundations of the vaccine remain constant. The shots are either made with flu viruses that have been inactivated, which means they’re not infectious, or—in the case of recombinant flu vaccines—they’re made without viruses at all. This means that you can’t get the flu from any type of shot.

Depending on the year, both three-component or four-component vaccines are available.

Three-component vaccines defend against three types of flu virus: an influenza A (H1N1), another influenza A (H3N2) and an influenza B virus. The four-component vaccines protect against these same viruses, plus an additional B virus. Your doctor will recommend you get either the three- or four-component vaccine depending on your age, the health of your immune system, allergies and other factors.

During some years the U.S. Food and Drug Administration (FDA) has recommended use of a nasal spray flu vaccine, also known as live attenuated influenza vaccine or LAIV. Although it was not on the CDC’s list of recommended vaccines for the 2016-2017 and 2017-2018 flu seasons, the CDC voted to add the nasal flu vaccine back to its list of recommended vaccines for adults for the 2018-2019 flu season.

In some years these recommendations differ for children. In May 2018 the American Academy of Pediatrics (AAP) announced that it expected the flu shot to be more effective than the nasal spray for the 2018-2019 season, and that most children should therefore receive the shot. 

But in March 2019, the AAP’s recommendations changed slightly. In advance of the 2019-2020 flu season, the organization said there was no longer one preferred flu vaccine and that both the flu shot and the nasal spray vaccine were effective for children 6 months and older.

For the 2019-2020 flu season, the FDA has determined that flu shots will include two types of influenza A (H1N1 and H3N2) and one or two types of influenza B as well, depending on the vaccine. You can stay up to date as more information comes out at

For adults over the age of 65, higher-dose vaccines may be recommended since they are stronger and more effective for people who have weakened immune systems. 

How is the flu vaccine selected?
The flu virus is constantly changing, so it’s necessary for researchers to reevaluate the expected strains each year, the CDC explains. The exact components of the vaccine, therefore, may change from year to year. The World Health Organization assembles a board of researchers from their own collaborating centers and other key laboratories—including the CDC and the Francis Crick Institute—to determine:

  • Which viruses are making people sick
  • How fast the viruses are spreading
  • The effectiveness of the previous vaccine

Once this information has been presented and reviewed—usually in February of each year—the FDA will make the official vaccine decision for the U.S. After that, manufacturing companies will begin creating the vaccine, a process that usually takes about six months. Physicians will typically know what the vaccine will contain in August or September and can usually begin administering it at the beginning of October, says Good.

Who needs the shot?
The CDC recommends that anyone six months or older get the flu vaccine. And for those who have an increased risk of flu-induced complications—like those under five years of age, those over the age of 65, pregnant women or those in nursing homes or other care facilities—it’s vital to adhere to flu vaccine recommendations.

There are some exceptions to the recommendations, though: Those who are under 6 months of age, allergic to the flu vaccine or allergic to flu vaccine ingredients like gelatin should not get the flu shot. And those who have had Guillain-Barré Syndrome in the past should talk with their doctor first.

“It's especially important for pregnant women to protect themselves,” Good says, “because if they get the flu while they’re pregnant, the risk of complications is much higher.” Once the baby is born, Good adds, it’s vital for a mother to have been vaccinated because if she has the flu, she can pass it along to her newborn.

It’s also imperative that those with the following conditions get a flu shot, because contracting the flu may worsen symptoms or lead to complications:

  • Asthma or chronic lung disease
  • Neurological conditions
  • Heart disease
  • Blood disorders
  • Endocrine disorders such as diabetes
  • Kidney or liver disorders
  • Metabolic disorders
  • Damaged immune system
  • Extreme obesity

​And if you’re allergic to eggs, it’s likely you’ll be able to get the year’s recommended flu shot without needing any observation afterwards unless you experience other side effects besides hives, like respiratory distress. Many flu shots and vaccines are manufactured using egg-based technology, explains the CDC, and therefore have small traces of egg proteins in them. But studies show that severe reactions related to egg allergies are unlikely.

Talk with your doctor to discuss your allergies and to determine the vaccine option that’s right for you. Some egg-free options are available.

The timing matters
So, you know that you need a flu shot, but some questions remain: When should you get it? And is getting the shot at one time of year more effective than another? The answers are complicated.

It’s always better to get the flu shot than not, regardless of when you get it. But in the ideal scenario, you’d get the shot before the flu starts to spread each year. According to the CDC, that’s in October. And because children age 6 months to 8 years will have to get two doses four weeks apart the first season they’re vaccinated, it’s beneficial to begin their vaccination process a bit earlier.

That said, depending on the year, the flu shot may still be effective even if you get it in January or later, so you should never think it’s too late to get the shot. It’s probably still worth it, since the flu continues to spread throughout the winter.

If you’re unsure about whether or not to get the flu shot based on your health profile, check with your doctor. There are few sure things in life, but getting the flu shot each year is pretty close to one of them. It might just save your life—and possibly the lives of others, too.

Medically reviewed in May 2019. Updated in January 2020.

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