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Beating Flu Season

Key takeaways:
~ Some people are more susceptible to different flu strains than others.
~ There are well-researched, natural options for fighting the flu that you may want to have on hand.

Members will see their genotype report below, plus additional solutions in the Lifehacks section. Consider joining today 

Flu season, genes, and solutions:

The flu goes around each year — usually in November/December and then again in Feb/March in the Northern Hemisphere. Some years it seems worse than others. For the past decade, with the flu vaccine available, 10 to 40 million people in the US have gotten the flu each year.[ref]

How do you know if it’s the flu?

If you are wondering whether it is the flu, Covid, or another virus, you could get tested for both the flu and Covid to see which one it is. The CDC website states you can’t tell them apart by symptoms.[ref]

Flu symptoms include:

  • Fever, chills
  • Fatigue
  • Body ache
  • Cough
  • Sore throat
  • Stuffy nose
  • Headache

Four types of flu viruses have been identified: Influenza A, B, C, and D.

Influenza is a negative-strand RNA virus in the family Orthomyxoviridae. Within each type, multiple strains are going around each year.[ref][ref] The exact flu strain changes each year by recombining parts of different strains.

  1. Influenza A (H1N1 or H3N2): Sometimes called swine flu, this variant usually arises from recombining H1N1 strains from birds, pigs, and humans.[ref]
  2. Influenza B: About 20-30% of flu infections each year are influenza B strains.[ref]
  3. Influenza C: Usually causes mild respiratory illness or is asymptomatic. Most people have antibodies to influenza C by the time they are teens.[ref]
  4. Influenza D: Mainly circulates in cattle and pigs.[ref]

So far this year (fall/winter 2022), about 30% of cases are influenza A(H1N1), with the rest being influenza A(H3N2).[ref]

Interestingly, several studies show that the majority of people exposed to a new flu strain don’t get the flu, or at least don’t get any symptoms. A study on the swine flu pandemic (2009) noted the “majority of people newly exposed to one of the most dangerous viruses to circulate in human populations in recent history… did not notice any symptoms.”[ref]

We have robust immune systems which fight off viruses in multiple ways. Plus, we all have slight genetic differences in immune system genes, giving some an advantage for certain flu strains.

Differences in immune system genes are a feature allowing parts of a population to survive new pathogens.

Cell entry and replication:

With Covid in the news for the past few years, we have all gotten a crash course in SARS-CoV-2 virology and how the virus enters the cell via the ACE2 receptor.

The flu virus is not as picky about needing a specific type of cell receptor for entry.

Hemagglutinin is a cell surface protein on the influenza virus that helps it to attach to the host cell. It attaches to glycans called sialic acid on the surface of cells in the respiratory tract.[ref] Sialic acids cause a negative charge on cell surfaces and help keep water at the cell’s surface. Thus, they are found in areas with a mucous membrane – such as the nose, lungs, and intestines. And this is where the flu virus easily enters the cell by endocytosis and replicates.

Inside the cell, the flu virus makes its way to the cell nucleus, where it uses the host’s RNA replication enzymes to transcribe the viral proteins for replication.[ref]

Transmission of the flu:

The flu is an airborne virus, spreading via aerosols and probably by direct contact.[ref]

Airborne transmission is defined as inhaling infectious viruses smaller than 5 μm at distances greater than 3-6 feet from the infected individual.

Influenza, RSV, rhinovirus, SARS-CoV, MERS, and Covid are all spread this way. Viral aerosol particles can linger in the air for hours to days.[ref]

Understanding airborne viruses can help explain how the flu is transmitted between people and why it is seasonal…

Why is the flu seasonal?

The question of why the flu always goes around about the same time in a region has puzzled researchers for years. There are theories on vitamin D levels, UV light changes, seasonal movement, and humidity changes.

For humidity, the theory is that lower humidity allows the flu aerosol particle size to become smaller and remain in the air longer. Viruses have specific humidity ranges where they are likely to linger in the air and be breathed in by people.

But seasonal relative humidity changes don’t tell the whole story. What feels like a humid day in Grand Junction, CO, would be considered a very dry day in Charleston, SC.

A recent study points towards the combination of humidity changes along with changes to the mucus membranes of people living in the area.

Take Florida, for example. For people whose noses and mucus membranes were used to more humidity, a drop in humidity will feel dry, and there will be changes to the mucus production in the noses adapted to the area. Similarly, Wyoming may always have less humidity than Florida’s driest day, but a change from 15% relative humidity to 8% will dry out Wyoming noses.[ref]

Genetics is the other key to who gets the flu, so let’s dig into the genes identified in research studies.

Beating Flu Genotype Report:

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You wake up with muscle aches and a fever… What are your options? The research studies are presented here so you can decide what is best for you.

Research on Natural Solutions for the Flu

Vitamin C:
A small study in healthy adults showed that 1,000 mg of vitamin C taken every hour for six hours at the onset of symptoms reduced symptoms by 85%. After the first six hours, participants took 1,000 mg three times a day.[ref]

Related article: Vitamin C genomics

Member Content:

  Log In

Why join Genetic Lifehacks?

~ Membership supports Genetic Lifehack's goal of explaining the latest health and genetics research.
~ It gives you access to the full article, including the Genotype and Lifehacks sections.
~ You'll see your genetic data in the articles and reports.

Join Here

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Gargling: Clinical trials on reducing respiratory infections
Does gargling really work for reducing upper respiratory infections? Learn more by looking at the research behind this easy preventive measure and deciding whether you should give it a shot.

Guide: Saving Money on Supplements
Five quick examples of how you could use your genetic data to dial in the supplements worth trying and which ones to skip for now.

Vitamin D, Genes, and Your Immune System
Vitamin D is more than just a ‘vitamin’. It is actually a hormone essential to many processes in your body – including your immune system. Learn how vitamin D helps the immune response to coronavirus, flu, and other respiratory viruses.



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About the Author:
Debbie Moon is the founder of Genetic Lifehacks. Fascinated by the connections between genes, diet, and health, her goal is to help you understand how to apply genetics to your diet and lifestyle decisions. Debbie has a BS in engineering from Colorado School of Mines and an MSc in biological sciences from Clemson University. Debbie combines an engineering mindset with a biological systems approach to help you understand how genetic differences impact your optimal health.