Key TakeawaysNew data show that young children get broad protection from annual flu vaccines.As kids grow up, however, the protection they get from the shots against other strains of the flu virus is not as consistent.Experts stress the importance of children and adults getting annual flu vaccines.

Key Takeaways

New data show that young children get broad protection from annual flu vaccines.As kids grow up, however, the protection they get from the shots against other strains of the flu virus is not as consistent.Experts stress the importance of children and adults getting annual flu vaccines.

The percentage of Americans who get an annualinfluenza vaccinehas stayed at around 50% for years.While most people can get a flu shot—from the youngest to the oldest—new research is showing that kids may get a special boost from it.

According to a new study, getting a flu vaccine every year provides young children with antibodies that offer broad protection against new strains—a benefit that older kids and adults don’t get.

An Overview of Influenza

The study, which was published in the journalCell Reports Medicine, analyzed data on immune responses of children between the ages of 3 and 15 years.

The researchers found that children were more likely to produce broadly protective antibodies against the flu when they were younger.

As they grew up, the antibodies they produced from eitherbeing infected with the flu or being vaccinatedagainst the virus were still effective against influenza, just less broad.

The researchers also compared antibody responses from the flu shot compared to thenasal spray vaccineand found that both were equally effective at producing protective antibodies.

How Flu Shots Work and Why They Sometimes Don’t

How the Flu Vaccine Works

Theflu vaccinemakes your body form antibodies against certain strains of the influenza virus. It takes about two weeks after you’re vaccinated for that protection to take effect.

The antibodies help protect you from getting infected orseriously illwith the strains of the flu that are circulating in a particular season.

Each year, researchers analyze data from around the world to try to figure out which strains of the flu virus will be the most common for the upcoming flu season. Then, they try to tailor the vaccine to match.

All flu vaccines in the United States protect against either three (trivalent) or four (quadrivalent) strains of the flu: an influenza A (H1N1) virus, an influenza A (H3N2) virus, and one or twoinfluenza Bviruses. (Only quadrivalent vaccines are available for the 2021–2022 flu season.)

2021-2022 Flu VaccineAccording to the Food and Drug Administration (FDA), the 2021-2022 flu vaccine is designed to protect against the following strains of the flu:An A/Victoria/2570/2019 (H1N1) pdm09-like virusAn A/Cambodia/e0826360/2020 (H3N2)-like virusA B/Washington/02/2019- like virus (B/Victoria lineage)A B/Phuket/3073/2013-like virus (B/Yamagata lineage)

2021-2022 Flu Vaccine

According to the Food and Drug Administration (FDA), the 2021-2022 flu vaccine is designed to protect against the following strains of the flu:An A/Victoria/2570/2019 (H1N1) pdm09-like virusAn A/Cambodia/e0826360/2020 (H3N2)-like virusA B/Washington/02/2019- like virus (B/Victoria lineage)A B/Phuket/3073/2013-like virus (B/Yamagata lineage)

According to the Food and Drug Administration (FDA), the 2021-2022 flu vaccine is designed to protect against the following strains of the flu:

A Universal Flu Vaccine Could Replace Your Yearly Shot

How Well Do Flu Shots Work?

The flu vaccine is different each year, which means itseffectivenesscan vary fromflu seasonto season.

Centers for Disease Control and Prevention (CDC) data show that the shot’s efficacy at preventing a flu infection has ranged from as low as 10% during the 2004–2005 flu season to as high as 60% during the 2010–2011 flu season.

Effectiveness from the 2019-2020 season—the most recent season that data is available for—shows that the vaccine was 39% effective at preventing the flu in people who received it.

The Importance of Flu Shots

Thomas Russo, MD, a professor and the Chief of Infectious Disease at the University at Buffalo, told Verywell Health that while the flu vaccine “isn’t perfect, it does help protect people from landing in the hospital.”

Russo added that children may have more of a broad antibody reaction to the flu vaccine simply because they haven’t been exposed to the flu often—if at all.

Thomas Russo, MDEveryone who is able should get their annual flu vaccine.

Thomas Russo, MD

Everyone who is able should get their annual flu vaccine.

Richard Watkins, MD, an infectious disease physician and professor of internal medicine at the Northeast Ohio Medical University, told Verywell that the situation is a bit different for adults because they “have more preexisting antibodies, which can inhibit vaccine responses."

Given the difference in immune responses, Watkins said that “it might be easier to develop a universal flu vaccine for children than adults.”

Infectious disease expertAmesh A. Adalja, MD, a senior scholar at the Johns Hopkins Center for Health Security, told Verywell that “the point is that annual flu vaccine induces antibodies that are broadly neutralizing.”

Adalja stressed that adults still do get benefits and antibodies from the vaccine, and that “it may be that children get more as their immune systems have not been primed” to respond to the virus the way adults have through continued exposure through vaccination and infection.

Russo said the study demonstrates the importance of adults and children getting their annual flu shot.“

We don’t want the take-home message to be that it’s futile for adults to get vaccinated against the flu—that’s not true,” said Russo. “Everyone who is able should get their annual flu vaccine.”

What This Means For YouChildren may get more broad protection from their annual flu vaccine than adults do, but people of all ages still benefit from getting a flu shot.

What This Means For You

Children may get more broad protection from their annual flu vaccine than adults do, but people of all ages still benefit from getting a flu shot.

Clinical Trial Shows Cell-Based Flu Shot Works Well in Kids

6 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.Flu vaccination coverage, United States, 2020–21 influenza season.Yegorov S, Celeste DB, Gomes KB, et al.Inactivated and live-attenuated seasonal influenza vaccines boost broadly neutralizing antibodies in children.Cell Rep Med.2022 Feb 15;3(2):100509. doi:10.1016/j.xcrm.2022.100509Centers for Disease Control and Prevention.Key facts about seasonal flu vaccine.Centers for Disease Control and Prevention.Seasonal influenza vaccine supply for the U.S. 2021-2022 influenza season.Food and Drug Administration.Influenza vaccine for the 2021-2022 season.Centers for Disease Control and Prevention.Past seasons vaccine effectiveness estimates.

6 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.Flu vaccination coverage, United States, 2020–21 influenza season.Yegorov S, Celeste DB, Gomes KB, et al.Inactivated and live-attenuated seasonal influenza vaccines boost broadly neutralizing antibodies in children.Cell Rep Med.2022 Feb 15;3(2):100509. doi:10.1016/j.xcrm.2022.100509Centers for Disease Control and Prevention.Key facts about seasonal flu vaccine.Centers for Disease Control and Prevention.Seasonal influenza vaccine supply for the U.S. 2021-2022 influenza season.Food and Drug Administration.Influenza vaccine for the 2021-2022 season.Centers for Disease Control and Prevention.Past seasons vaccine effectiveness estimates.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Centers for Disease Control and Prevention.Flu vaccination coverage, United States, 2020–21 influenza season.Yegorov S, Celeste DB, Gomes KB, et al.Inactivated and live-attenuated seasonal influenza vaccines boost broadly neutralizing antibodies in children.Cell Rep Med.2022 Feb 15;3(2):100509. doi:10.1016/j.xcrm.2022.100509Centers for Disease Control and Prevention.Key facts about seasonal flu vaccine.Centers for Disease Control and Prevention.Seasonal influenza vaccine supply for the U.S. 2021-2022 influenza season.Food and Drug Administration.Influenza vaccine for the 2021-2022 season.Centers for Disease Control and Prevention.Past seasons vaccine effectiveness estimates.

Centers for Disease Control and Prevention.Flu vaccination coverage, United States, 2020–21 influenza season.

Yegorov S, Celeste DB, Gomes KB, et al.Inactivated and live-attenuated seasonal influenza vaccines boost broadly neutralizing antibodies in children.Cell Rep Med.2022 Feb 15;3(2):100509. doi:10.1016/j.xcrm.2022.100509

Centers for Disease Control and Prevention.Key facts about seasonal flu vaccine.

Centers for Disease Control and Prevention.Seasonal influenza vaccine supply for the U.S. 2021-2022 influenza season.

Food and Drug Administration.Influenza vaccine for the 2021-2022 season.

Centers for Disease Control and Prevention.Past seasons vaccine effectiveness estimates.

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