Strengthen your shot: tips for boosting flu vaccine effectiveness

Every year, millions roll up their sleeves for the flu shot—but how can we ensure those vaccinations pack the strongest punch? While vaccine effectiveness varies by season and circulating strain (which we can’t control), lifestyle factors can actively enhance the body’s immune response to the flu vaccine.

Think of it this way: the flu vaccine gives your immune system a recipe for protection, but how well your body follows those instructions depends on its physiological state. It’s like giving someone a recipe – if their kitchen is stocked and ready, the results will be delicious. If not, then good luck with that paella!

So, let’s dive into the science and explore how to optimize your immune system to make every dose count.

Your flu shot is the recipe—your body is the kitchen. Stock it well with sleep, nutrition, calmness and movement to make immunity deliciously effective. #FluSeason #ImmuneBoost #SASlife
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Prioritize Sleep

Sleep is not passive, it’s immunologically powerful. While you rest, your body ramps up cytokine production, regulates inflammation and strengthens immune memory. Because sleep and immunity are so closely linked, how well you sleep can impact how well a vaccine works.

Studies show that getting insufficient sleep, especially in the two nights before your shot, is associated with fewer antibodies months later. On the flip side, quality sleep the night of vaccination can double immune cell production. Even better? Those antibodies can stick around for up to a year.

To get the most out of your flu shot, aim for consistent, restorative sleep (ideally 7-9 hours nightly) the week before and after vaccination.

Nourish with Immune-Boosting Foods

What you eat can impact how your body responds to vaccines. Nutrients like vitamin C, vitamin D, zinc, protein and antioxidants are essential for a strong immune system.

A balanced diet, rich in colorful fruits and vegetables, whole grains and quality proteins, helps your body build a better defense and reduce low-grade inflammation. This inflammation is often a sign of poor metabolic health, which can impair immune function and weaken vaccine effectiveness.

In one study, animals with poor metabolic health at the time of vaccination had immune cells that did not work properly – even after switching to a healthy diet. But when animals ate well prior to vaccination, their immune cells responded more effectively to the flu virus.

While there is no single “flu-fighting” food, fruits and vegetables are especially powerful, packed with nutrients that support antibody production. And broccoli sprouts, rich in sulforaphane, may boost your body’s production of virus-fighting proteins after vaccination.

Before rolling up your sleeve, prep your plate to support your immune system, filling it with a variety of colorful, nutrient-dense foods (and limit ultra-processed foods like cookies, chips, candy and soda).

Manage Stress

The immune system responds to stress in various ways. While acute stress can temporarily boost immune function, chronic stress tends to do the opposite, making it more difficult for your body to generate a strong antibody response to vaccines.

In fact, one study found that individuals with higher stress levels 8-10 days after getting a flu shot had 12-17% fewer antibodies than their less-stressed counterparts. Interestingly, stress levels in the 2 days before and on the day of vaccination did not seem to impact antibody production.

So, as you’re preparing for your flu shot, prioritize stress management – especially in the week after vaccination. Deep breathing, meditation, coherence, walking in nature, journaling, laughing with a friend, taking a bath, or even throwing a mini dance party are all powerful ways to regulate stress and support your body’s immune system.

Stay Physically Active

Just as sleep creates a restorative environment for immunity, exercise offers an active way to support it. While even a single workout can spark short-term changes in immune function, consistent physical activity delivers the most lasting benefits.

Among it’s many perks, regular physical activity delays immunosenescence – a fancy word for the gradual decline in immune function that occurs with aging. One hallmark of this process is a weakening response to vaccines.

In a study at Iowa State University, participants who did a 90-minute session of mild-to-moderate aerobic exercise (brisk walking or stationary biking) immediately after getting a flu shot had nearly double the antibody levels for four weeks later. They also found that 90 minutes seems to be the sweet spot: shorter (45-minute) and longer (3-hour) workouts did not produce the same antibody boost.

As you plan your next vaccine, try to schedule a walk or bike when you leave the clinic – and be sure to keep regular movement part of your routine year-round.

Support Your Gut

The gut microbiome is a dynamic ecosystem of microbes living in your intestines. These tiny organisms help digest food, absorb nutrients and even influence your mood and behavior. Remarkably, the gut is also home to 70-80% of your body’s immune cells, making it a key player in regulating immune function.

Eating a diet rich in prebiotics and probiotics – found in foods like yogurt, kefir, fermented foods, fruits and vegetables – is one way to foster a healthy gut environment. For other science-backed strategies to improve gut health, check out this blog.

Supplementing with prebiotics and probiotics may further enhance gut health, directly improving flu vaccine effectiveness. A systematic review and meta-analysis found that taking these supplements in the weeks surrounding vaccination increases the likelihood of a stronger antibody response by up to 20%.

While more research is needed to determine the most effective strains and dosages, it’s worth considering a pre/probiotic supplement in the weeks leading up vaccination – and definitely worth keeping gut-friendly foods on your plate all year long.

When to Schedule Your Shot

It takes about two weeks for your body to build up protective antibodies after getting the flu vaccine. For maximum protection during peak flu season (typically December – February in the U.S.), schedule your flu shot in late September or October.

Getting vaccinated too early (like July or August) may mean your immunity wanes before flu activity peaks. On the other hand, getting it too late could leave you vulnerable if exposed to the flu virus before your body has a chance to build up enough antibodies.

Final Thoughts

Optimizing flu vaccine effectiveness isn’t just about the shot – it’s about targeting and supporting the whole system around it. Leveraging daily choices like getting proper sleep, eating nourishing foods, managing stress, staying active and supporting gut health can help your body become a more responsive, resilient environment for the vaccine and your immune system to do their job.

And, of course, don't forget to wash your hands! For more tips on flu prevention and vaccine timing, visit the CDC’s seasonal flu guide.

Healing Roots Chicken Soup

Makes 6 servings
PRINT RECIPE

Ingredients

2-3 lemongrass stalks (optional)
1 Tbsp sesame or avocado oil
1 Tbsp minced ginger
2 cloves garlic, minced
1 cup shredded carrots
5 oz shiitake mushrooms
¼ tsp salt
6-8 cups chicken stock
1 Tbsp soy sauce or coconut aminos
1½ lbs chicken breasts or tenders, thinly sliced
3 heads baby bok choy, chopped

Optional Garnishes: freshly squeezed lime juice, sliced green onion, chopped cilantro

Instructions

Prepare lemongrass, if using. Remove tough outer leaves until you reach the softer, pale yellow center. Trim off the hard, woody root end and green, grassy top. Use the flat side of a knife or a meat mallet to lightly smash the stalk. Set aside.

Heat oil in a large pot or Dutch oven. Add garlic and ginger and cook for about 1 minute.

Add carrots, mushrooms and salt and cook until slightly soft, about 2-3 minutes.

Add chicken stock, soy sauce and lemongrass.

Bring to a boil. Add thinly sliced chicken and bok choy, return to a boil and let simmer until chicken is cooked through, 5-10 minutes depending on thickness.

Remove and discard lemongrass stalks.

Serve as is or over cooked noodles of choice.

Garnish with lime juice, green onion and/or cilantro, if desired.