In the United States, flu season typically lasts from October to May. The flu virus affects people of all ages each year, and symptoms include coughing, runny nose, fever, chills, body aches, and headache. Symptoms can be mild or severe and usually last for 3 to 7 days.

The flu might not cause serious problems for some, but there’s a risk of complications in individuals age 65 and older. The reason for this is that older adults tend to have a less robust immune system.

If you’re over age 65, here’s what you can do to strengthen your immune system to help ward off the flu and other viruses.

Getting your annual flu shot is one of the best ways to protect yourself from the flu. The flu shot is shown to reduce the risk of hospitalizations in older adults by 40 percent and can reduce the overall risk of flu infection by 40 to 60 percent.

The vaccine works by stimulating your immune system to create antibodies. This helps protect against infection.

There are different types of flu vaccines. Some vaccines are available to people of all ages.

Fluzone High-Dose and Fluad Quadrivalent are specifically for adults ages 65 and older.

  • Fluzone High-Dose. This vaccine contains four times more antigens than the standard vaccine. Your body creates more antibodies to fight the flu in response to higher levels of antigens. People with the high dose vaccine had 24 percent fewer flu infections compared to those who had a standard flu shot.
  • Fluad Quadrivalent. This vaccine has an added ingredient called MF59 adjuvant. This boosts the immune response and also creates more antibodies to protect you from the flu.

The flu virus changes every year. This means the flu shot changes as well based on predicted virus strains. To stay protected, it’s important to get vaccinated every year. You can get the flu shot from a professional at your doctor’s office, a pharmacy, or a flu clinic in your area.

You can also ask your doctor about pneumococcal vaccines to protect against pneumonia and meningitis.

Eating a balanced, nutrient-rich diet is an important way to boost your immune system. This includes eating plenty of fruits and vegetables, which contain nutrients and antioxidants to promote good health.

Many different vitamins and minerals play a role in maintaining the immune system. The best way to meet your needs is to eat a variety of foods.

Specific nutrients that play a role in immune health include:

  • B vitamins. B vitamins are found in dairy products, grains, meats, eggs, and beans. Vitamin B12 deficiency is common in older adults. Ask your doctor if you need a supplement.
  • Vitamin C. Vitamin C is found in many fruits and vegetables, especially red and orange types and citrus fruits. Most people are able to get enough from food and usually a supplement is not needed.
  • Selenium. Selenium is an antioxidant that is found in small amounts in many foods. Sources include nuts, meats, and grains.
  • Zinc. Zinc is a mineral is found in oysters, cheese, beans, lentils, and beef. Most people are able to get enough from their diet but in special cases, a supplement may be recommended.

There is some evidence that a Mediterranean-style diet can support good immune function. A Mediterranean diet can also play a role in helping to prevent and manage chronic diseases.

This particular diet includes plenty of fruits, vegetables, whole grains, and beans. It also emphasizes healthy fats from sources such as fish, olive oil, olives, nuts, and seeds.

Malnutrition reduces immune function, which increases the risk of illness, according to 2019 research. If you are having trouble eating enough or getting enough variety, talk to your doctor. You can also work with a registered dietitian if you need some extra help.

It’s important to keep moving as you get older since activity has many benefits. It can keep you strong and mobile as you age. Exercise also increases blood circulation and has an anti-inflammatory effect on the body.

Additionally, regular physical activity is associated with better immune function, according to 2020 research. It’s believed that being active increases the body’s ability to detect harmful invaders.

For older adults, the Centers for Disease Control and Prevention (CDC) recommends:

  • at least 150 minutes of moderately intense activity every week
  • muscle building exercises twice a week

Everyone starts from a different place. If you are not currently active, any increase in activity counts. Start slowly to get your body used to moving more and consider working with a physical therapist if you have pain or other challenges.

Chronic stress can have many negative effects on the body, including lowering your immune response. When under stress, the body increases the production of a hormone called cortisol.

Cortisol helps the body deal with stressful situations. It also limits certain bodily functions that aren’t essential in a fight-or-flight situation. This includes the immune system.

Over time, this limited function of the immune system can make you more susceptible to infection.

It’s difficult to live a life that is completely free of stress, so learning how to manage stress when it arises may be the most helpful option. Some options include:

  • making time for things that you find enjoyable and relaxing, like reading or gardening
  • exercising
  • trying mindfulness or meditation strategies

If you’re having trouble coping with stress, consider working with a therapist.

Quality sleep becomes more important with age. Getting enough sleep can improve brain function, concentration, and memory.

Conversely, sleep deprivation can cause a multitude of issues, like reducing the effectiveness of the immune system.

To improve the quality of your sleep, try a few of these methods:

  • make sure your room is dark, quiet, and cool
  • keep a regular bedtime routine when possible
  • limit daytime naps to about 45 minutes
  • avoid caffeine later in the day
  • limit alcohol, as it may interfere with sleep quality

If you are dealing with insomnia or other issues that keep you awake at night, talk with your doctor to see if there could be any underlying causes.

Your body is home to trillions of tiny organisms. Your microbiome is made up of a variety of beneficial bacteria, fungi, viruses, and protozoa. Most are found in the digestive tract (gut) and play many important roles in your overall health.

Your gut is directly connected to your immune system. When your gut microbiome is in good shape, your immune system is better able to detect and fight off infection, according to 2018 research.

Here are some things you can do to maintain a healthy gut microbiome:

  • eat lots of fiber-rich foods, such as vegetables, fruits, beans, whole grains, nuts, and seeds
  • try fermented foods, such as kefir, yogurt, kombucha, tempeh, miso, kimchi, and sauerkraut
  • only use antibiotics when necessary

The chemicals in cigarettes are known to damage lung tissue and increase the risk of cancer. Smoking can also suppress your immune response, according to 2016 research. People who smoke are more likely to have respiratory illnesses, such as the flu, bronchitis, and pneumonia.

To improve your immune system function, consider taking steps to quit or reduce smoking. There are many smoking cessation aids such as nicotine patches or nicotine gum. Some people also find therapy or support groups helpful.

You can also talk with your doctor about medications to reduce cravings for cigarettes.

Being outside has so many benefits for your health. Many people find that time in nature helps to reduce their stress. Another bonus of outdoor time is vitamin D from moderate sun exposure.

Vitamin D helps strengthen the immune system. When your vitamin D levels are adequate, they may help prevent inflammation and some autoimmune diseases.

A 2017 review suggests vitamin D may also help prevent certain infections. When more than 11,000 people were analyzed, researchers found that those who supplemented vitamin D had fewer respiratory infections.

Outside of salmon and beef liver, there are not many food sources that are naturally high in vitamin D. Depending on where you live, your skin color (melanin, or skin pigmentation, plays a role in the amount of vitamin D synthesis that occurs from sun exposure), and how much time you spend outside, it may be hard to get enough vitamin D from food and from the sun.

If your vitamin D levels are low, your doctor may recommend a supplement.

Strengthening your immune system, especially when you’re over 65, can help protect you from the flu and a variety of other viruses.

Staying active, eating a good mix of fresh foods, spending a moderate amount of time outside in the sun, and getting as much quality sleep as possible can help keep your immune system in good shape.