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Why Get The Flu Shot Every Year?

There’s lot of discussions about influenza (flu) shots. The experts recommend we get one every year. Although some people still refuse to get one. So, what’s the deal with flu shots anyway? Why should you get one every year? Here’s what to know.

What is the flu virus?

Influenza (flu) is a respiratory virus. And it’s a very resilient virus. It can live on surfaces for up to 24 hours. It can also live in air droplets. The colder the air, the longer it lives. And this may explain why winter is prime influenza season. This makes it easily spread from person to person.1-2

There are 4 types of flu viruses: A, B, C, and D.3-5

Type D mainly affects cattle. So, for our purposes, we don’t have do worry about it. Type C affects humans, but only causes mild respiratory symptoms. So, we’re not worried about it either.4

What we have to be concerned about are types A and B. They can spread fast during the winter months.4

Let’s look at Influenza A.

It can spread from animals to humans. It can also spread from humans to humans. It can cause epidemics and pandemics. It may also cause severe flu symptoms.4

There are two types of influenza A. They are defined by proteins on their surfaces called: 3

Hemagglutinin (H) Neuramindase (N)

These types are divided into subtypes.3

H = H1 through H18N = H1 through H11

Put an H and an N together and you get an influenza A virus. Two common subtypes known to cause epidemics are H1N1 and H3N2.

Let’s look at influenza B.

Influenza B viruses are broken down into strains. The ones in the air now are B/Yamagata and B/Victoria. There are a variety of other strains, any of which can make it’s way around in a typical flu season.3

Influenza B viruses can only spread from human to human. It’s not responsible for pandemics like those caused by influenza A viruses. But, it is often responsible for causing annual flu epidemics. It used to be considered less severe than influenza A. Although, newer studies seem to indicate it can be just as severe.4

So, how does the flu spread?

It cannot spread on it’s own. To do this, it must replicate. And to replicate, it must attach itself to a cell. So, let’s assume you inhaled an H1N1 flu virus. 6

The virus attaches to an airway cell. It quickly slips into the cell. It uses your cells genetic code and turns your cell into an H1N1 making factory. Hundreds of H1N1 viruses are made. This continues until the virus overwhelms the cell. The cell dies. The cell bursts. Hundreds of H1N1 viruses are free to infect other cells. So, the virus spreads to other cells, turning each one into an H1N1 factory 6

Your body responds by causing airway inflammation. Inflammation is good. It traps and kills the viruses. But, it’s also what causes your flu symptoms: fever, chills, body aches, headaches, runny nose, fatigue, coughing, and sneezing.7

How do flu viruses cause epidemics and pandemics?

I emphasize coughing and sneezing. The H1N1 virus relies on this to spread from person to person. This usually starts when the air starts to get cold in November. It usually ends when the air starts to get warmer in March. And this is your typical cold and flu season.8-9

A neat thing is our bodies develop H1N1 antibodies. If we inhale the same virus again, H1N1 antibodies will attach to the virus and render it harmless. So, you’d think this would render the H1N1 virus harmless and unable to cause future epidemics and pandemics.6

But, researchers now know that it can cause future epidemics and pandemics. In fact, the H1N1 virus is believed to have caused both the 1918 and the 2009 flu pandemics. So, how did this happen? Why was the same flu subtype able to strike again?9

The answer is that flu viruses are smart. The H1N1 virus may end the season in swine. It may pick up swine DNA. This DNA is added to the H1N1 virus. This changes it just enough so our H1N1 antibodies won’t recognize it. And this is how the same flu subtypes can cause pandemics 90 years apart.9

And it can happen again.

In fact, an influenza pandemic can start anywhere at any time. Also, it’s known to hit asthmatics harder than non-asthmatics. This is true even if you have mild asthma.9-10

This is why we emphasize: “Get your flu shots!!!”

Thankfully, flu researchers are smarter than flu viruses. Researchers have studied flu epidemics and pandemics. They now know why they happen. They know there are many flu viruses. And they know flu viruses can change. So, this makes it important to make a new flu vaccine for each flu season.

Researchers use educated guesses to predict what flu viruses are in the air this year. They make a new virus based on this educated guess. And that’s why they recommend you get your flu shot every year — especially if you have asthma.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The Asthma.net team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

  1. https://www.nhs.uk/common-health-questions/infections/how-long-do-bacteria-and-viruses-live-outside-the-body/
  2. https://www.nytimes.com/2007/12/05/health/research/05flu.html
  3. “Types of influenza viruses,” CDC, https://www.cdc.gov/flu/about/viruses/types.htm, accessed 11/7/18
  4. “Influenza B Symptoms: What Is Type B Influenza?” Healthine.com, https://www.healthline.com/health/influenza-b-symptoms#types, accessed 11/7/18
  5. “The 2009 H1N1 Pandemic: Summary Highlights, April 2009-April 2010,” CDC, https://www.cdc.gov/h1n1flu/cdcresponse.htm, accessed 11/7/18
  6. Alcamo, Edward I, “Fundamentals of Microbiology,” 5th Edition, 1997, Addison Wessley Longman, Inc., pages 329-331, 587-608
  7. https://www.cdc.gov/flu/consumer/symptoms.htm
  8. https://www.cdc.gov/flu/about/season/index.html
  9. http://www.who.int/influenza/en/
  10. https://www.cdc.gov/flu/asthma/index.htm

Comments

  • emmejm
    10 months ago

    As a kid, even with my asthma, I never had flu shots because my mom only believes in vaccines for stuff like polio and measles (not an anti-vaxxer, just stubborn and underinformed). She always told me and my sister that we didn’t need flu shots because we had strong immune systems (spoiler: we don’t).

    As a young adult, I continued to refuse flu shots because I didn’t think I needed one (I wasn’t aware of concepts like “herd immunity” and still held my mother’s false belief that I had a strong immune system even with all evidence to the contrary) and didn’t feel like being stabbed unnecessarily. It was only after a graduated college and switched to a new GP that someone sat me down and explained how important the flu shot was, especially for an asthmatic. Since then, I haven’t missed one and finally convinced my sister to get a shot in November.

    I still tend to catch colds and flus in the winter, but the symptoms usually aren’t so bad and I spend less time in urgent care getting breathing treatments.

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