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How does the immune system work?

Your immune system is an incredibly sophisticated system that has been protecting you since before you were born.
And your immune system needs to be sophisticated – when your body is made up of more bacteria than it is human cells. 
Your immune system needs to be able to tell the difference between friend and foe to help keep those ‘good bacteria’ in our guts doing the wonderful job they do.

What is the immune system?

The immune system is a collection of cells, proteins, enzymes and chemical messengers that work together to fight off infections. There are two layers to your immune response – and both are essential. These are known as the innate and acquired immune systems.

The innate immune system  

The first layer of defence against invading microbes is known as innate immunity. This is the equivalent of bodyguards and protective clothing. You’ve seen your innate immune system at work. The mucus that starts green and turns yellow then clear you get better following infection with the common cold? All part of the innate immune response. The innate immune system uses mucus in the airways, oils on the skin and acid inside the vagina to protect the skin surfaces from infection. Your skin is your largest organ, and it works as a barrier between your highly sensitive inside world, and the highly contaminated outside world. Your innate immune system also includes generic fighter cells – which act like bodyguards. They identify the microbes that shouldn’t be there, disable them, and then call for back-up using specialised chemical messengers that travel quickly around the body. The innate immune system is fast. Cells known as macrophages and neutrophils are constantly patrolling exposed surfaces to catch invaders as quickly as possible. The faster the body responds – the more likely the body is to kill the invader before it can cause a lot of damage.

The acquired immune system

The acquired immune response plays a critical role too. Your acquired immune system has two branches:

  1. The antibody factory
  2. The virus (and cancer) terminators

Antibody factories (and what they do)

If you have followed the news at all recently you will have heard a lot about antibody testing. This is because during an infection your body produces tiny proteins called antibodies.
These tiny proteins are designed with little protein arms that are the *exact* shape of part of the invading microbe…so they float around the body on mass and when they find something they fit to exactly (think a key in a lock or those shape sorting toys a toddler has) they bind.
When they bind they stop the invader from being able to attach to human cells, and they target them for destruction by the patrolling macrophages from the innate immune system #teamwork.
So why are there concerns about the effectiveness of antibody tests? If the body is pumping antibodies into all of the cavities of our body, surely this is a great thing to measure? It is. But it doesn’t last long.
So does that mean immunity to COVID-19 won’t last long? We don’t know yet, but there is still hope coming from another part of the immune system. 

The T cell response aka the Terminator

So it’s not really called the terminator…but it’s not far off. The second branch of the acquired immune system is based on T cells. These cells primarily target human cells which label themselves as distressed/failing/infected.
Natural killer cells can bind to viral infected cells and terminate them using controlled cell death – a process known as apoptosis. This is much healthier for the body than what viruses do, which is burst out of cells when they have made hundreds of their virus babies and create a cascade of inflammation.
Other T cells involved in the immune response include T helper cells which help to manage the immune response.
It is usually the T cells that cause auto-immune disease when regulation goes wrong.

Reference (for both paragraphs):

How does an immune response work?

Let’s look at the key players in the immune response and exactly what they do.


These cells patrol the body looking for invaders. They have a very flexible cell membrane that binds to invaders and pulls them into their insides (cytoplasm) where they dissolve them using enzymes. They also alert the immune system to the presence of an invader so your body can start revving up its white blood cell army.


Work in a similar way to macrophages. They can travel anywhere in the body.


These are cells of the acquired immune system that manufacture antibodies. Antibodies are the proteins that travel around the body binding to, and inactivating the invader. They are specific only to the invader they have been told about, so their response is much slower than the cells in the innate immune response (a couple of days behind).


These cells help to halt viral invasions. As viruses replicate inside your cells, they essentially hide from the immune system (and most drugs). The T-cells, once alerted by the innate immune response, can see when a cell is in distress and can kill the cell, and also the viral factory hidden inside. 


These are not lymphocytes. In fact, they’re not white blood cells at all. Cytokines are the chemical messengers that help activate and wind down different parts of the immune system. Think of them as the postal service of the immune response – sending messages between cells of the immune system.

The parts of the immune system:

group of people hugging

Your immune system covers your entire body, so let’s look at some examples of key places your body wages war against pathogens (microbes that cause disease).

  • Lymph nodes:  You have lymph nodes in locations all over your body. White blood cells patrol the liquid passing through them (called lymph) for any microbes that shouldn’t be there. If they find something, the immune system is alerted. During an infection you can often feel them through the skin, particularly the ones in your neck, under your armpits and in your groin.
  • Spleen: White blood cells are stored here.
  • Tonsils: Ideally located to target infections via the mouth and nose – the tonsils trap invaders and hold white blood cells to rapidly initiate a co-ordinated immune response.
  • Thymus: Involved in maturing T cells. Plays an important role in preventing auto-immunity during fetal development.
  • Bone Marrow: Millions of white blood cells are produced here.
  • Skin: Mucous traps invaders and hair-like cells called cilia move the mucus towards the throat where it’s swallowed and ends up in the stomach. Sweat, tears and vaginal secretions contain enzymes that can also kill invaders.
  • Stomach: The stomach has an incredibly acidic environment measuring in around pH1-2. This kills almost all infectious microbes.


Can supplements help our immune system?

Let’s have a closer look at some of the vitamins, minerals and herbs we know play a role in our immune system:

  • Zinc:

    Zinc is essential for the healthy functioning of your immune system. It is involved in signalling between the innate and acquired immune system. It’s estimated 2 billion people worldwide suffer from zinc deficiency. Those living in developing countries and the elderly are most at risk. Zinc is not stored in the body and so needs to be consumed regularly.

  • Vitamin A: 

    Deficiency in vitamin A affects both innate and adaptive immunity. It’s believed that vitamin A deficiency affects the production of the different types of white blood cells (leucocytes) which affects macrophages (the cell eaters), B cells (that make antibodies) and the T cells (terminate infected cells). Deficiency in vitamin A affects both innate and adaptive immunity. It’s believed that vitamin A deficiency affects the production of the different types of white blood cells (leucocytes) which affects macrophages (the cell eaters), B cells (that make antibodies) and the T cells (terminate infected cells).

  • Vitamin C: half of a lemon

    Thought to have a general effect on the immune system, vitamin C may reduce the intensity and length of a cold if taken early enough. The body cannot store vitamin C so you need a regular intake from food.

  • Vitamin D: 

    Deficiency is associated with increased autoimmunity and increased susceptibility to infection. It can be made by the skin during the summer but in some parts of the world, supplementation is required during the winter months.

  • Echinacea:

    A common herbal remedy used in the US thought to stimulate the adaptive immune system.

  • American Ginseng:

    Contains Ginsenosides and polysaccharides which are believed to have immune-boosting properties.

  • Andrographis

    More commonly seen in ancient oriental and ayurvedic medicines. This herbal remedy is believed to have antimicrobial, anti-inflammatory and immunostimulant activity.

In summary

Your immune system is a genius interconnected network of white blood cells that works best when it has the nutrients it needs to perform.
RENEW Immune Support formula contains zinc, american ginseng and andrographis.

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