The immune system has taken on an unexpected role in the midst of the covid-19 pandemic.
It is not for less. This complex network of cells, tissues and organs is the main weapon our body has to defend itself against SARS-CoV-2, the new coronavirus that causes this disease.
Like any other part of the body, the immune system ages over the years, leaving us more vulnerable to infections, cancer, and all kinds of diseases.
This is one of the reasons – in addition to the prevalence of pre-existing diseases – why people over 65 are at higher risk of contracting COVID and developing a more virulent form of the disease.
However, the age of the immune system does not necessarily match chronological age. And as we get older, this discrepancy can become even wider.
“We can have individuals who are chronologically 80 years old and have an immune system that looks like a 62-year-old person. Or quite the opposite: a 60-year-old person whose immune system looks like that of a person of a much older age,” he explains. to BBC Mundo Shai Shen-Orr, an immunologist at the Israel Technion Institute of Technology.
What’s interesting, moreover, is that we can slow down your aging (or possibly reverse your age) by following a series of simple steps.
But before we see how to achieve it, let’s remember how it works and how and what deteriorates with age.
Fewer B and T cells
The immune system has two arms, each one made up of different types of cells.
On the one hand, there is the so-called innate response, which is the first line of defense that is activated almost immediately when it detects the presence of a foreign organism.
Anything we can do to maintain immune health helps in the fight against covid-19.
This answer contains “neutrophils, that attack mainly bacteria; monocytes, which help organize the immune system, alerting other immune cells that there is an infection, and then there are the NK (the asesin cells), whose job is to fight viruses or cancer. These three cells do not they work so well when we get older “, explains to BBC Mundo Janet Lord, director of the Institute of Inflammation and Aging at the University of Birmingham, in the United Kingdom.
On the other hand is the adaptive response, composed of lymphocytes T y B that fight a specific pathogen. This response takes a few days to kick in, but once it does, it will remember the pathogen for the future and fight it again, if it reappears.
How our immune system works and how it fights the coronavirus
“As you get older, you make fewer new lymphocytes, which are what you need to fight a new infection like SARS-CoV-2,” says Lord.
“And even the ones that your body created in the past to fight another infection don’t work very well either,” he adds.
That is, aging causes a decline in all the functions of the immune system.
The innate response produces a little more cells but these do not work as well, and the adaptive response produces fewer B lymphocytes (which are made in the bone marrow and are responsible for producing antibodies) and fewer T lymphocytes (which are produced in the thymus and identify and kill pathogens or infected cells).
The decrease in T cells is due to the fact that “the thymus begins to shrink at 20 years of age. It gets smaller and smaller and when you reach 65 or 70 years, only 3% of it remains (in the body) “says Lord.
The loss of cells that store the memory of pathogens causes us to lose not only the ability to respond to infection, but also to the vaccines that prevent them as we age.