Colds, flu, RSV, and COVID, it’s that time of year when viruses run rampant and many of you reading this will be down for the count with their annoying and sometimes scary symptoms.
Others of you will get nary a sniffle all winter.
What makes the difference, genes, luck or hand-washing habits?
While what you do every day absolutely matters for your immune health, we’ve known for some time, and the latest research confirms, that our genes play a role in determining how well our bodies fight off viruses and infections.
As with all things genetics, you may carry variants that increase your risk of getting sick but knowing which ones they are and knowing exactly what nutritional support and lifestyle habits help them work optimally, can dramatically shift the odds in your favor.
The Genetic Foundation of Immunity
Your immune system is an incredibly complex network, and like every other system in your body, it’s influenced by your DNA. Certain genetic variations can affect how quickly and effectively your body responds to viral threats like the common cold, flu, or other seasonal infections.
Among the most impactful genes for viral immunity are:
VDR (Vitamin D Receptor): This gene determines how efficiently your body uses vitamin D—one of the most crucial nutrients for immune function. Here’s the catch: if you have certain variants in your VDR gene, you could be taking loads of vitamin D supplements, but your body simply can’t take it up effectively. This is why some people feel dramatically better with vitamin D supplementation while others see no benefit despite the same dosage.
ACE2: You’ve probably heard about this gene in relation to COVID-19, as it’s the receptor that many viruses use to enter our cells. Genetic variations in ACE2 can influence your susceptibility to viral infections and how severely your body responds when infected.
HLA (Human Leukocyte Antigen): This is your immune system’s identification system—the genetic complex that helps your body distinguish between “self” and “invader.” Variations in HLA genes affect how quickly and accurately your immune system recognizes and responds to viruses. Some variants are associated with stronger immune responses, while others may leave you more vulnerable to infections.
IFNg (Interferon Gamma): Interferons are your body’s first line of defense against viruses. This gene influences the production of interferon gamma, a crucial signaling molecule that activates your immune cells when a virus invades. Genetic variants here can affect how robustly your body mounts an antiviral response.
TYK2: This gene plays a key role in immune cell signaling and communication. When a virus enters your body, your immune cells need to “talk” to each other quickly and coordinate an effective response. Variants in TYK2 can affect this cellular communication, influencing both your susceptibility to infection and your risk of autoimmune conditions.
NOS Inducible nitric oxide (iNOS) is an enzyme that produces large amounts of nitric oxide (𝑁𝑂) in response to stimuli like inflammation, infection and hypoxia. It is essential for the innate immune response to fight pathogens.
Your genes are set in stone but your outcomes are not
While these genetic variants can increase your risk of frequent infections or sluggish immune response, they’re not your destiny. Research reveals that genetics accounts for only about 10-25% of immune function—the other 75-90% is determined by environmental factors and lifestyle choices entirely within your control.
Think of it this way: your genes load the gun, but your daily habits determine whether it fires.
This is particularly important to understand because generic health advice doesn’t work equally well for everyone. What supports your coworker’s immune system might actually harm yours. For instance, fermented foods are often touted as immune-boosting, but some people experience histamine responses that actually worsen their health. Vitamin D supplementation is another example, standard doses might be ineffective for some genetic profiles while being exactly right for others.
When Genetics Meets Action: Why Personalized Matters
Understanding your genetic variants transforms vague health advice into targeted, effective action. Rather than following generic wellness trends that may or may not work for your body, MyHappyGenes® genetic testing reveals what your specific immune system needs.
Whether you have VDR, HLA, IFNg, TYK2, NOS or variants in the other genes that combine to provide a strong immune response or a weak one, lifestyle habits and the right nutritional support makes all the difference in fighting off seasonal viruses.
The critical insight is this: knowing your genetics allows you to stop wasting time and money on interventions that won’t work for your body, and focus on what actually will. This is why genetic testing isn’t just interesting—it’s actionable.
The Daily Choices That Move the Needle
Regardless of your genetic variants, research has identified key lifestyle factors that significantly impact immune resilience:
Sleep: This is non-negotiable. People who sleep less than 7 hours per night are nearly three times more likely to develop a cold when exposed to the virus. During sleep, your body produces and distributes key immune cells.
Stress Management: Chronic stress suppresses immune function by elevating cortisol. Even if you have favorable immune genes, chronic stress can override that advantage.
Nutrition: A diet rich in colorful vegetables, fruits, lean proteins, and healthy fats provides the building blocks your immune system needs. Processed foods and excess sugar actively suppress immune function.
Exercise: Moderate exercise enhances immune surveillance and reduces inflammation. But be careful—over-exercising without adequate recovery can temporarily suppress immunity.
Hydration: Your mucous membranes are a crucial barrier against viruses. Staying well-hydrated keeps them functioning optimally.
The challenge is that these factors affect everyone differently based on their genetic makeup. The amount of sleep you need, which foods best support your immune function, and which types of exercise benefit you most—all of these can vary based on your DNA.
The MyHappyGenes® Advantage
For years, we’ve been told to “boost our immune system” with generic advice that works for some people but not others. The reason is simple: we’re not all working with the same genetic blueprint.
The MyHappyGenes® Healthy Genes report identifies your specific genetic variants related to immune function, including the key genes that influence your viral susceptibility and immune response. When you know your genetic predispositions, you can stop guessing and start implementing the specific strategies your body actually needs.
Even more importantly, you’ll discover which popular health trends won’t work for you, saving you time, money, and frustration. Generic recommendations like “take vitamin D” or “eat fermented foods” might be harmful or ineffective for your specific genetic profile, while other interventions that don’t work for most people might be exactly what your body requires.
The Bottom Line
You might carry genes that make you more susceptible to catching colds and flu, or that make your immune response slower and less effective. But those genes aren’t your destiny, they’re your instruction manual.
This cold and flu season, the question isn’t whether you have immune-related genetic variants, many of us do. The question is whether you know which variants you carry and what specific actions will keep you healthy despite them.
Because while we can’t change our DNA, we can absolutely change how our genes express themselves through our daily choices. And when those choices are informed by your actual genetic makeup rather than generic advice, that makes all the difference between spending your winter sick in bed or enjoying the season in good health.
