Opinion: Immune System And Ageing — Why We Get More Vulnerable As We Age

One of the key changes in ageing is the reduced production of immune cells. The bone marrow and thymus, which are responsible for producing immune cells, decrease in efficiency over time. 

Representational image.

Source : Pixabay

By Dr Parinita Kaur

As we age, our immune system undergoes significant changes that can affect its ability to protect the body from infections, diseases, and even cancers. These changes, known as immunosenescence, involve both a decline in immune function and alterations in immune responses, which contribute to increased vulnerability to illness.

One of the key changes in ageing is the reduced production of immune cells. The bone marrow and thymus, which are responsible for producing immune cells, decrease in efficiency over time. The thymus, particularly, shrinks and becomes less effective at producing T cells, which are essential for fighting infections and cancer. As a result, older adults often have fewer naïve T cells, making it harder for the immune system to recognise and respond to new pathogens.

In addition to a decrease in immune cell production, there is also a decline in the function of both T cells and B cells. T cells, which help identify and destroy infected or cancerous cells, become less efficient in older individuals. This can lead to a weakened immune response, and a reduced ability to fight off infections or tumours. Similarly, B cells, which produce antibodies to neutralise pathogens, may become less effective in older adults, resulting in a weaker defence against infections and a reduced response to vaccinations.

Another significant change with ageing is chronic inflammation, often referred to as inflammaging. This low-grade, persistent inflammation is linked to a variety of age-related diseases, such as cardiovascular disease, diabetes, and Alzheimer’s disease. Chronic inflammation is thought to arise from the accumulation of cellular damage, immune dysregulation, and an overactive response to low-level infections.

The immune system’s ability to respond to vaccines also declines with age. Older adults may have a reduced ability to produce antibodies after vaccination, making them less protected against diseases like the flu or pneumonia. This highlights the importance of targeted vaccines for older adults, such as those with higher doses or adjuvants to boost the immune response.

Overall, the ageing process affects the immune system’s efficiency, making it harder to fend off infections, detect new pathogens, and manage inflammation. To support immune health, older adults can focus on maintaining a healthy lifestyle, staying active, eating a balanced diet, managing stress, and keeping up with recommended vaccinations.

The writer is principal consultant & unit head, Internal Medicine, at Max Super Speciality Hospital, Dwarka.

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