How to Boost Your Immune System During Flu Season

Flu season rolls around like clockwork every year, but getting sick does not have to feel inevitable. Behind the scenes, your immune system is doing a lot and the winter cold and flu season can act as your annual immune stress test. While you can’t “hack” your immune system and there’s no magic pill, you can support your immunity to give your body the best chance at fighting sickness. This is your friendly, evidence-based guide to staying well—plus a clear breakdown of the questions everyone Googles at 2 in the morning.

The immune system is multi-layered. Innate and adaptive immunity work together to fight infections. The innate immune system acts as the first responder; it recognizes pathogens quickly and generally. The adaptive immune system learns and develops specific and targeted responses over time through the use of antibodies and memory cells.

The flu (AKA, influenza) is a contagious respiratory infection caused by influenza A or B viruses. It can cause mild to severe illness, and can lead to health complications or death in extreme cases. It spreads through tiny droplets made when those with the flu cough, sneeze, talk, and have close contact with others. You can catch the flu by touching your own mouth, nose, or eyes after touching a surface or object with the flu virus on it.

It’s also possible to infect others before symptoms develop and up to 7 days after (with the first 3 days of illness being the most contagious). Bottom line? It spreads, and fast. Young children and anyone with weakened immune systems may have more severe symptoms and be contagious for longer.

First of all—sorry. Getting the flu while pregnant sucks. Pregnancy can alter immune function and make symptoms feel worse for some people. Getting the flu while pregnant carries a higher risk of complications (pneumonia, dehydration, hospitalization), so early action is key. 

How to treat the flu while pregnant:

1. Contact your primary care provider or midwife. They might recommend antivirals within the first 48 hours. They will also be able to monitor the baby’s health and help you navigate any complications. If you have shortness of breath, chest pain, extreme weakness, reduced fetal movement, or trouble keeping fluids down for more than 8 hours, seek urgent care immediately.

2. Rest! Preserve energy for the immune system and for the growing baby.

3. Hydrate. Water and electrolytes can help—but watch your intake if high blood pressure or preeclampsia are present are a concern.

4. Manage your fever. If you have a fever of more than 38°C (100°F), talk to your doctor. Acetaminophen (Tylenol) is the preferred medication for pregnant women with fevers. Avoid ice exposure, but lukewarm or cool baths and compresses are safe to stabilize fevers.

5. Eat simply. Generally, drinking broths and eating cooked vegetables, lean protein, and fruit can help the body heal without making you feel more sick.

6. Call your naturopathic doctor. Pregnancy changes the rules of supplementation. The usual supplement routine may not be safe or suitable right now. Your ND can customize gentle, safe immune support alongside your primary care provider. 

It can be tricky to tell the difference between a cold, the flu, and COVID-19.They are all contagious respiratory illnesses, but are caused by different viruses and can share many symptoms.

Common cold

The common cold (rhinovirus) is usually milder than the flu and tends to occur slowly over a few days, with symptoms like a runny or stuffy nose, sneezing, low-grade fever, and a scratchy sore throat. You might feel “off” and tired, but can still typically function, albeit while holding tissues.

Influenza

The flu presents with a fast onset and often occurs with fever, chills, fatigue, headaches, nausea/vomiting, and body/muscle aches. Most people are out of commission for a couple of days. The flu can result in complications such as pneumonia, bacterial infections, or hospitalizations. 

COVID-19

COVID-19 overlaps quite a bit with flu symptoms but is even more contagious. The signs and symptoms can be the same, so testing is needed to confirm a diagnosis of either. Shortness of breath and digestive symptoms can be more common. One of its more distinctive features is a sudden loss of taste or smell, which is relatively uncommon in cold and flu. The contagious period can last up to 14 days. Unlike the others, COVID fatigue can linger long after the infection clears, making it a viral house guest who overstayed its welcome.

It’s crucial to have the foundations in place for a strong immune system to decrease the frequency and severity of viral illnesses (including the flu). Other than getting the flu shot annually (which is recommended), here are a few more things you can do to help boost your immune system:

• Prioritize sleep
  Sleep means repair mode for the body. Aim for 7 to 9 hours a night and keep your room cool and dark. Avoid late-night scrolling (we know—easier said than done!), since it messes with melatonin production, disrupting immunity. Even a couple of nights of poor sleep can make you more susceptible to catching infections. Quality sleep is a necessity, not a luxury!
  
  
• Reduce chronic stress
  Chronic stress keeps our main stress hormone, cortisol, high for too long. This suppresses our immune response and slows recovery in general. Engage in stress reduction habits daily like breathwork, social connection, physical stretching, mindfulness and meditation, time management, making time for fun and hobbies—even 10 minutes of “me time” can work wonders if done consistently. The goal is to bring balance to the nervous system to take you out of survival mode, which allows your immune system to be sharp.
  
  
• Stay hydrated
  Hydration keeps your mucosal barriers (nose, throat, lungs—your body’s frontline workers against airborne viruses) working properly. Two to -3 litres of water daily supports lymphatic circulation, meaning immune system cells move more efficiently throughout the body, clearing waste and fighting infection. Consider adding electrolytes for even more hydration, especially if you are fighting early flu symptoms. 
  
  
• Move your body
  Moderate-intensity, regular exercise can boost immunity by reducing inflammation and helping the circulation of white blood cells. A daily walk, mobility work, pilates, or resistance training 3 to 4 times weekly can be supportive for the immune system. But, avoid overtraining: it can boost the stress response and temporarily decrease immunity. Movement as prevention is playing the long game, but is a great defense, especially when paired with good recovery and nutrition. 
  
  
• Resolve deficiencies, optimize micronutrients, and support your immune system
  Certain nutrients and herbs have strong evidence for supporting immunity. Your immune system uses vitamins, minerals, and antioxidants as fuel and cofactors (helpers) to fight infection and help you recover. You may experience a more severe illness and slower recovery if you have some nutrient deficiencies because the body struggles to defend itself efficiently in a depleted state. With optimized nutrient status, your immune system is better equipped for cold and flu season.

Here are some of the heavy-hitters for you to add to your winter toolkit (or your year-round health support) when it comes to immune function. Be sure to check with your healthcare provider to ensure safety before making any changes to your routine. Keep in mind, these can’t replace healthy lifestyle habits, but they may help reduce the severity of viral illness.

NAC supports glutathione production, which repairs cell damage after infections. Research shows NAC may reduce the severity and length of the flu when used early on in infection. It also supports healthy inflammatory signalling, balancing the immune system during a viral infection. 

Research shows that Vitamin D helps your body create antimicrobial peptides that can decrease viral replication and strengthen immunity—all while balancing inflammation during viral illness. Because Vitamin D supports the immune system at multiple levels, those with solid Vitamin D levels may have a lower risk of catching the flu and less severe symptoms.

Zinc supports defense from viruses and immunity in the respiratory tract. Research shows that Zinc may reduce the length of symptoms and speed up recovery when dosed early on in infection. Zinc helps to maintain healthy mucosal barriers and immune signalling which are key to defending against respiratory bugs.

Iron is essential for making healthy red blood cells and supporting immune cell metabolism. While iron is supportive for a healthy immune response, pathogens can feed on it, so, our bodies actually lower the amount of Iron in our bloodstream during infections—even though Iron deficiency can result in poorer recovery. Having optimal Iron levels as a preventative measure (or to correct a deficiency) helps support energy, oxygen delivery, and immune resilience leading into flu season. 

Vitamin C supports antioxidant defense and immunity in the respiratory tract. Vitamin C maintains healthy mucosal barriers like the lining of the nose and throat, and supports the defense strategies of the immune system. Research shows that Vitamin C doesn’t prevent infection, but it may reduce the severity of symptoms. 

Packed with flavonoids, antioxidants, and anthocyanins, elderberry may relieve symptoms and shorten the duration of them when started early in infection.

Ginger has well-documented anti-inflammatory, anti-nausea, and antioxidant effects which support symptom relief while promoting circulation and providing pain relief for body aches.