Thanks to the COVID-19 pandemic, everyone around the world is making efforts to keep their immune system strong and effective. 

However, the immune system is also affected by intrinsic and uncontrollable factors, such as ageing. Let’s find out what happens to your immune system as you age.

What Happens To The Immune System as You Age?

Your immune system is a collection of cells, tissues, and organs. It helps in defending your body against toxins and foreign tissues, fighting against infections caused by viruses or bacteria, and preventing the proliferation of cancer cells. 

The immune system performs these functions by making cells and antibodies (proteins that defend your body against foreign agents) that act against these harmful substances.

There are two branches of the immune system: innate immunity and adaptive immunity. 

1. Innate Immunity 

Innate immunity is the defence system you are born with, and it forms your first line of defence against foreign agents. 

Research suggests that immunosenescence, the gradual deterioration of the immune system with age, causes chronic, systemic inflammation (a response by your immune system that prevails even after infection or injury) and compromises innate immunity. 

In younger people, the immune system switches to an anti-inflammatory response after initial infection or injury. However, this does not appear to happen as effectively in older adults. 

2. Adaptive Immunity

Adaptive immunity involves immune cells and antibodies that attack foreign agents and remember them, so it can prevent another infection in the future. 

T cells are an important part of adaptive immunity. When an infection occurs, undifferentiated T cells identify the specific pathogen involved and differentiate into specialised cells that can mount immune responses against the same pathogen during future infections.

This pool of undifferentiated T cells steadily diminishes as you age, as more and more T cells become specialised for tackling particular infections. Thus, adaptive immunity steadily loses its ability to defend against pathogens. It also becomes difficult for your body to recover from infections. 

What Are The Signs of a Declining Immune System?

Here are some signs that you might observe as you get older:

  • Your body does not respond well to vaccines. Your T cells become fewer in number as you age, and most vaccines need naive T cells to work effectively. 

  • You get sick more often. Lesser number of immune cells and reduced effective communication between them as you age means that your body may take longer to react to infection by pathogens.

  • You can take longer to heal. Recovering from illness, injury, or infection becomes much slower as your body does not produce an effective number of immune cells, responsible for speeding up the healing process.

Further, you might be at an increased risk of developing an autoimmune disorder (a condition in which your immune system mistakenly attacks its own healthy cells) or cancer, as its ability to detect and correct cell defects declines. 

What Can Help You Stay Healthy?

Remember to:

  • Sleep well: It is important to get at least 7 to 8 hours of sleep every night, as lesser or lower quality sleep lowers your immunity. 

  • Quit smoking: Smoking has a major role in weakening your immune system, making you more prone to infection or disease. 

  • Eat well: Eat a well-balanced, nutritious diet full of fresh, whole foods. Good nutrition is important for the working of your immune system. 

  • Exercise: Exercising daily can help in keeping your body fit and healthy, which in turn makes your immune system stronger. 

  • Reduce stress: Long-term stress can reduce your body’s immune response and also impact it indirectly through reduced sleep and altered eating habits. 

  • Stay away from sick people: When you get old, you are more likely to fall ill upon exposure to microbes. Stay away from contagious environments and people.

Lastly, do not skip vaccination, even if it may have reduced efficacy in old age. It is important to get vaccinated to lower your risk of severe illness, especially during this pandemic. 


Disclaimer: This article is written by the Practitioner for informational and educational purposes only. The content presented on this page should not be considered as a substitute for medical expertise. Please "DO NOT SELF-MEDICATE" and seek professional help regarding any health conditions or concerns. Practo will not be responsible for any act or omission arising from the interpretation of the content present on this page.