How Does the Flu Shot Keep You From Getting Sick?

For most of us, getting the flu shot is just a regular part of fall. Pumpkins, leaves changing colors, hot cocoa  the flu shot. We’ve put our trust in the flu shot for decades (since 1933, to be exact). But how does it work, exactly?

Influenza (a.k.a. the flu) is a potentially serious disease that can lead to hospitalization or even death, should circumstances not go your way. Every flu season is different  every flu strain is different  but getting an annual seasonal flu vaccine is the best strategy we have to protect against it.

How does the vaccine work, exactly?

Flu vaccines help your body create weapons, called antibodies, that help fight the virus when you’re exposed to it. They actually develop in the body around two weeks after vaccination, which is why it’s important to get the flu shot promptly at the beginning of flu season (in October and before Halloween).

Scientists develop vaccine strains based on the versions of the virus they think are most likely to show up that particular season. This is a bit of a guessing game, to be honest, but doctors have gotten pretty good at applying influenza research to make good selections.

Which viruses am I protected against?

Traditional flu vaccines (called “trivalent” vaccines) protect against three flu viruses: influenza A (H1N1), influenza A (H3N2) and influenza B. You may also come across vaccines called “quadrivalent” vaccines which protect against an additional B virus.

The U.S. Centers for Disease Control (CDC) suggests no preference between different forms of the flu vaccine for the upcoming 2018-2019 influenza season. Inactivated influenza vaccine (IIV), recombinant influenza vaccine (RIV) and live attenuated influenza vaccine (LAIV) are all fair game.

So, should I get one?

Yes. Almost unarguably. The CDC, as well as the World Health Organization (WHO), recommend yearly vaccination for nearly everyone over the age of six months  particularly those who are considered to be high risk. This includes young children, older people, pregnant women and those with certain chronic health conditions.

Where to get your flu shot:


Chrissie R
Chrissie R12 days ago

I get my flu shot every year on my birthday...and I got mine yesterday! Haven't had the flu...or any of it's complications in light years.
No side effects in all those many years either...many people still aren't educated about vaccines despite informationally correct articles.

Christine D
Christine D12 days ago

There are so many things wrong with this article. First most people don't die from the flu; they die from complications they develop due to a weak immune system, like pneumonia. But go ahead and get your flu shot if you don't mind cancer-causing formaldehyde and brain-toxic heavy metals including aluminum and mercury coursing through your body.

Edith B
Edith B12 days ago

I get mine!

Danuta W
Danuta W12 days ago

Thanks for sharing.

Chad A
Chad Anderson13 days ago

Thank you.

Anne Moran
Anne M13 days ago

Think I'll pass...

Rita Delfing
Rita Delfing13 days ago

I will pass thanks. I suppose there is a time and place, elderly, if you fly a lot, have a blood count problem, low immunity. I'll let my immune system take care of me. My Uncle got GBS from a flu shot, that sealed the deal for me on getting one.

Lee T.
Lee T.13 days ago

Within the recent decade or so, there has been much concern about Flu shots (other vaccinations, as well). After reading many articles on the topic, I wonder if there are some people with a genetic mutation (or some other biophysical condition) that may have an impact on their immune system/brain-blood system which causes so much problems?

Sherry Kohn
Sherry K13 days ago


Carol S
Carol AWAY S13 days ago

I get mine as soon as it's available!