Have you ever wondered why some people never seem to get the flu when it is going around? Turns out that our genes play a role in both our immune response to the flu virus and the virus’s ability to replicate in us.
Simply put, some people are just more susceptible to getting the flu than others.
Both the H1N1 and H3N2 flu strains are going around this year. The CDC’s interactive map shows when the flu becomes widespread in parts of the US.
Genetic variants affecting susceptibility to H3N2:
A 2016 study looked at genetic variants in some of the genes involved in an immune response. It found that variants in IL17 (interleukin-17), IL28 (interleukin-28), and IL1B (interleukin-1 Beta) increased the risk of getting the flu. Keep in mind that even if you are at half the normal risk, you can still get the flu if you are exposed to it, especially if you have a compromised immune system.
Check your genetic data for rs2275913 (23andMe v4, v5)
- G/G: typical risk for H3N2 flu (compared to A/A)
- A/G: typical risk for H3N2 flu (compared to A/A)
- A/A: ~ half the risk for H3N2 flu[ref]
Members: Your genotype for rs2275913 is —.
Check your genetic data for rs16944 (23andMe v4, v5):
- A/A: typical risk for H3N2 flu
- A/G: typical risk for H3N2 flu
- G/G: less than half the risk for H3N2 flu[ref]
Members: Your genotype for rs16944 is —.
Check your genetic data for rs8099917 (23andMe v4, v5):
- T/T: typical risk for H3N2 flu
- G/T: ~ half the risk for H3N2 flu
- G/G: ~ half the risk for H3N2 flu[ref]
Members: Your genotype for rs8099917 is —.
Genetic variants impacting H1N1 susceptibility:
The CCR5 gene codes for a protein on the surface of white blood cells. CCR5 is a chemokine receptor involved in our immune response. People who carry the CCR5delta32 variant are more resistant to HIV infection.
The CCR5delta32 variant has also been investigated in H1N1 flu cases. Several studies found a link to susceptibility and increased the severity of flu symptoms for people who carry the variant.[ref][ref] But at least one study found no link to disease severity.[ref]
Check your genetic data for i3003626 (23andMe v4,v5 [also known as rs333 and CCR5delta32]):
- Insertion/Insertion (either II orGTCAGTATCAATTCTGGAAGAATTTCCAGACA / GTCAGTATCAATTCTGGAAGAATTTCCAGACA): typical
- Insertion / Deletion (either DI or -/GTCAGTATCAATTCTGGAAGAATTTCCAGACA): possibly higher risk of flu or increased severity of flu[ref][ref]
- Deletion / Deletion (either DD or –): resistance to the common strains of HIV
Members: Your genotype for i3003626 is —.
The CD55 gene codes for the complement decay-accelerating factor, which regulates the complement system on immune cells. A variant of CD55 has been associated with the severity of H1N1 infection.[ref]
Check your genetic data for rs2564978 (23andMe v4 only):
- C/C: typical severity of flu
- C/T: typical severity of flu
- T/T: increased severity of H1N1 flu infection[ref]
Members: Your genotype for rs2564978 is —.
The CDC recommendations for the flu include staying away from people who have the flu and washing your hands often. Seems like common sense advice.
Elderberry syrup is a folk remedy for the flu and colds. A randomized double-blind, placebo-controlled study found that using elderberry syrup (15ml) relieved symptoms 4 days earlier than placebo. You can find elderberry syrup online and at local stores like Walmart.
A study (in rats) found cinnamon essential oil to decrease flu virulence and deaths.
Recap of your genes:
|Gene||RS ID||Risk Allele||Your Genotype||Notes About Risk Allele|
|IL17A||rs2275913||A||--||A/A: ~ half the risk for H3N2 flu|
|IL28||rs16944||G||--||G/G: half the risk for H3N2 flu|
|IL1B||rs8099917||G||--||Half the risk for H3N2 flu|
|CCR5||i3003626||D||--||higher risk of flu or increased severity of flu|
|CD55||rs2564978||T||--||T/T: increased severity of H1N1 flu infection|
Related Articles and Genes:
Every year about 3 to 5 million people get the flu, and this results in about 250,000 to 500,000 deaths worldwide. One common prescription medication for the flu is Tamiflu, also known as oseltamivir. There are a couple of genetic variants that influence the way that oseltamivir works.
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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 and also 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.