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.
- Influenza A (H1N1 or H3N2): Sometimes called swine flu, this variant usually arises from recombining H1N1 strains from birds, pigs, and humans.[ref]
- Influenza B: About 20-30% of flu infections each year are influenza B strains.[ref]
- Influenza C: Usually causes mild respiratory illness or is asymptomatic. Most people have antibodies to influenza C by the time they are teens.[ref]
- 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:
Members: Log in to see your data below.
Not a member? Join here.
Why is this section is now only for members? Here’s why…
Member Content:
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
Lifehacks:
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:
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
Related Articles and Topics:
Chronic Sinus Infections: Genetics, Reasons, Solutions
Genetics plays a role in the likelihood of having chronic sinus problems. This article looks at the genetic reasons driving some people to have chronic sinus infections.
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.
References:
CDC. “Weekly U.S. Influenza Surveillance Report.” Centers for Disease Control and Prevention, 18 Nov. 2022, https://www.cdc.gov/flu/weekly/index.htm.
Chong, Yong Pil, et al. “Association of Mannose-Binding Lectin 2 Gene Polymorphisms with Persistent Staphylococcus Aureus Bacteremia.” PLoS ONE, vol. 9, no. 3, Mar. 2014, p. e89139. PubMed Central, https://doi.org/10.1371/journal.pone.0089139.
Choudhary, Manohar Lal, et al. “Functional Single-Nucleotide Polymorphisms in the MBL2 and TLR3 Genes Influence Disease Severity in Influenza A (H1N1)Pdm09 Virus-Infected Patients from Maharashtra, India.” Viral Immunology, vol. 35, no. 4, May 2022, pp. 303–09. PubMed, https://doi.org/10.1089/vim.2021.0179.
Clohisey, Sara, and John Kenneth Baillie. “Host Susceptibility to Severe Influenza A Virus Infection.” Critical Care, vol. 23, Sept. 2019, p. 303. PubMed Central, https://doi.org/10.1186/s13054-019-2566-7.
Gaitonde, David Y., et al. “Influenza: Diagnosis and Treatment.” American Family Physician, vol. 100, no. 12, Dec. 2019, pp. 751–58. www.aafp.org, https://www.aafp.org/pubs/afp/issues/2019/1215/p751.html.
Gorton, H. C., and K. Jarvis. “The Effectiveness of Vitamin C in Preventing and Relieving the Symptoms of Virus-Induced Respiratory Infections.” Journal of Manipulative and Physiological Therapeutics, vol. 22, no. 8, Oct. 1999, pp. 530–33. PubMed, https://doi.org/10.1016/s0161-4754(99)70005-9.
Harnett, Joanna, et al. “The Effects of Sambucus Nigra Berry on Acute Respiratory Viral Infections: A Rapid Review of Clinical Studies.” Advances in Integrative Medicine, vol. 7, no. 4, Dec. 2020, pp. 240–46. PubMed Central, https://doi.org/10.1016/j.aimed.2020.08.001.
Ibricevic, Aida, et al. “Influenza Virus Receptor Specificity and Cell Tropism in Mouse and Human Airway Epithelial Cells.” Journal of Virology, vol. 80, no. 15, Aug. 2006, pp. 7469–80. DOI.org (Crossref), https://doi.org/10.1128/JVI.02677-05.
Jariwalla, R. J., et al. “Suppression of Influenza A Virus Nuclear Antigen Production and Neuraminidase Activity by a Nutrient Mixture Containing Ascorbic Acid, Green Tea Extract and Amino Acids.” BioFactors (Oxford, England), vol. 31, no. 1, 2007, pp. 1–15. PubMed, https://doi.org/10.1002/biof.5520310101.
Jefferson, Tom, et al. “Neuraminidase Inhibitors for Preventing and Treating Influenza in Adults and Children.” The Cochrane Database of Systematic Reviews, no. 4, Apr. 2014, p. CD008965. PubMed, https://doi.org/10.1002/14651858.CD008965.pub4.
Keshavarz, Mohsen, et al. “Association of Polymorphisms in Inflammatory Cytokines Encoding Genes with Severe Cases of Influenza A/H1N1 and B in an Iranian Population.” Virology Journal, vol. 16, no. 1, June 2019, p. 79. PubMed, https://doi.org/10.1186/s12985-019-1187-8.
Keynan, Y., et al. “The Role of Polymorphisms in Host Immune Genes in Determining the Severity of Respiratory Illness Caused by Pandemic H1N1 Influenza.” Public Health Genomics, vol. 16, no. 1–2, 2013, pp. 9–16. www.karger.com, https://doi.org/10.1159/000345937.
Keynan, Yoav, et al. “Chemokine Receptor 5 Δ32 Allele in Patients with Severe Pandemic (H1N1) 2009.” Emerging Infectious Diseases, vol. 16, no. 10, Oct. 2010, pp. 1621–22. PubMed Central, https://doi.org/10.3201/eid1610.100108.
Krawitz, Christian, et al. “Inhibitory Activity of a Standardized Elderberry Liquid Extract against Clinically-Relevant Human Respiratory Bacterial Pathogens and Influenza A and B Viruses.” BMC Complementary and Alternative Medicine, vol. 11, Feb. 2011, p. 16. PubMed, https://doi.org/10.1186/1472-6882-11-16.
Lee, Nelson, et al. “IFITM3, TLR3, and CD55 Gene SNPs and Cumulative Genetic Risks for Severe Outcomes in Chinese Patients With H7N9/H1N1pdm09 Influenza.” The Journal of Infectious Diseases, vol. 216, no. 1, July 2017, pp. 97–104. PubMed Central, https://doi.org/10.1093/infdis/jix235.
Levy, Emily R., et al. “Evaluation of Mannose Binding Lectin Gene Variants in Pediatric Influenza Virus-Related Critical Illness.” Frontiers in Immunology, vol. 10, 2019, p. 1005. PubMed, https://doi.org/10.3389/fimmu.2019.01005.
Liu, Lei, and Bo Ning. “The Role of MBL2 Gene Polymorphism in Sepsis Incidence.” International Journal of Clinical and Experimental Pathology, vol. 8, no. 11, 2015, pp. 15123–27.
Liu, Runxia, et al. “Influenza D Virus.” Current Opinion in Virology, vol. 44, Oct. 2020, pp. 154–61. PubMed Central, https://doi.org/10.1016/j.coviro.2020.08.004.
Loeb, Mark, et al. “Surgical Mask vs N95 Respirator for Preventing Influenza among Health Care Workers: A Randomized Trial.” JAMA, vol. 302, no. 17, Nov. 2009, pp. 1865–71. PubMed, https://doi.org/10.1001/jama.2009.1466.
Macknin, Michael, et al. “Elderberry Extract Outpatient Influenza Treatment for Emergency Room Patients Ages 5 and Above: A Randomized, Double-Blind, Placebo-Controlled Trial.” Journal of General Internal Medicine, vol. 35, no. 11, Nov. 2020, pp. 3271–77. PubMed, https://doi.org/10.1007/s11606-020-06170-w.
Mehrbod, Parvaneh, et al. “Quercetin as a Natural Therapeutic Candidate for the Treatment of Influenza Virus.” Biomolecules, vol. 11, no. 1, Dec. 2020, p. 10. PubMed Central, https://doi.org/10.3390/biom11010010.
Noda, Tatsuya, et al. “Gargling for Oral Hygiene and the Development of Fever in Childhood: A Population Study in Japan.” Journal of Epidemiology, vol. 22, no. 1, Jan. 2012, pp. 45–49. PubMed Central, https://doi.org/10.2188/jea.JE20100181.
Parisi, Giuseppe Fabio, et al. “Nutraceuticals in the Prevention of Viral Infections, Including COVID-19, among the Pediatric Population: A Review of the Literature.” International Journal of Molecular Sciences, vol. 22, no. 5, Feb. 2021, p. 2465. PubMed Central, https://doi.org/10.3390/ijms22052465.
Past Seasons Estimated Influenza Disease Burden | CDC. 18 Oct. 2022, https://www.cdc.gov/flu/about/burden/past-seasons.html.
Radonovich, Lewis J., et al. “N95 Respirators vs Medical Masks for Preventing Influenza Among Health Care Personnel: A Randomized Clinical Trial.” JAMA, vol. 322, no. 9, Sept. 2019, pp. 824–33. PubMed, https://doi.org/10.1001/jama.2019.11645.
Rawangkan, Anchalee, et al. “Anti-Influenza with Green Tea Catechins: A Systematic Review and Meta-Analysis.” Molecules, vol. 26, no. 13, June 2021, p. 4014. PubMed Central, https://doi.org/10.3390/molecules26134014.
Rs1800450 – SNPedia. https://snpedia.com/index.php/Rs1800450. Accessed 18 Nov. 2022.
Sadeghsoltani, Fatemeh, et al. “Zinc and Respiratory Viral Infections: Important Trace Element in Anti-Viral Response and Immune Regulation.” Biological Trace Element Research, vol. 200, no. 6, 2022, pp. 2556–71. PubMed Central, https://doi.org/10.1007/s12011-021-02859-z.
Sahoo, Maheswata, et al. “Identification of Suitable Natural Inhibitor against Influenza A (H1N1) Neuraminidase Protein by Molecular Docking.” Genomics & Informatics, vol. 14, no. 3, Sept. 2016, pp. 96–103. PubMed Central, https://doi.org/10.5808/GI.2016.14.3.96.
Satomura, Kazunari, et al. “Prevention of Upper Respiratory Tract Infections by Gargling: A Randomized Trial.” American Journal of Preventive Medicine, vol. 29, no. 4, Nov. 2005, pp. 302–07. PubMed, https://doi.org/10.1016/j.amepre.2005.06.013.
Serman, E., et al. “Spatial Variation in Humidity and the Onset of Seasonal Influenza Across the Contiguous United States.” GeoHealth, vol. 6, no. 2, Feb. 2022, p. e2021GH000469. PubMed Central, https://doi.org/10.1029/2021GH000469.
Shon, Ji-Hong, et al. “Effect of Itraconazole on the Pharmacokinetics and Pharmacodynamics of Fexofenadine in Relation to the MDR1 Genetic Polymorphism.” Clinical Pharmacology and Therapeutics, vol. 78, no. 2, Aug. 2005, pp. 191–201. PubMed, https://doi.org/10.1016/j.clpt.2005.04.012.
Swaminathan, Kavya, et al. “Binding of a Natural Anthocyanin Inhibitor to Influenza Neuraminidase by Mass Spectrometry.” Analytical and Bioanalytical Chemistry, vol. 405, no. 20, Aug. 2013, pp. 6563–72. PubMed, https://doi.org/10.1007/s00216-013-7068-x.
Tong, Xiang, et al. “Association between the Mannose-Binding Lectin (MBL)-2 Gene Variants and Serum MBL with Pulmonary Tuberculosis: An Update Meta-Analysis and Systematic Review.” Microbial Pathogenesis, vol. 132, July 2019, pp. 374–80. PubMed, https://doi.org/10.1016/j.micpath.2019.04.023.
Tsybalova, Liudmila M., et al. “Influenza B: Prospects for the Development of Cross-Protective Vaccines.” Viruses, vol. 14, no. 6, June 2022, p. 1323. PubMed Central, https://doi.org/10.3390/v14061323.
Wu, Wenjiao, et al. “Quercetin as an Antiviral Agent Inhibits Influenza A Virus (IAV) Entry.” Viruses, vol. 8, no. 1, Dec. 2015, p. 6. PubMed Central, https://doi.org/10.3390/v8010006.
Yamada, Hiroshi, et al. “Gargling with Tea Catechin Extracts for the Prevention of Influenza Infection in Elderly Nursing Home Residents: A Prospective Clinical Study.” Journal of Alternative and Complementary Medicine (New York, N.Y.), vol. 12, no. 7, Sept. 2006, pp. 669–72. PubMed, https://doi.org/10.1089/acm.2006.12.669.
Zúñiga, J., et al. “Genetic Variants Associated with Severe Pneumonia in A/H1N1 Influenza Infection.” The European Respiratory Journal, vol. 39, no. 3, Mar. 2012, p. 10.1183/09031936.00020611. PubMed Central, https://doi.org/10.1183/09031936.00020611.
https://web.stanford.edu/group/virus/1999/rahul23/replication.html. Accessed 18 Nov. 2022.