How your immune system prevents the flu

How your immune system prevents the flu

You’re probably already aware that your immune system plays protecting you against threats including bacteria, parasites causing infectious diseases viruses – including the flu (1). But, exactly what does your immune system look like? And how does it help you fend off the flu?

Think of your immune system is a mixed task force. It’s made up of your skin, mucus, tiny hairs and various types of white blood cells, amongst other things. These work together to defend you against foreign invaders, including the virus that causes the flu.

Your skin provides your first line of defence – a physical barrier that is able to capture and kill any invaders that try to penetrate it (2). So how do invaders, such as the flu virus, successfully penetrate your body?

Your airway provides one route for them. However, this 'ports of entry' has well-developed defences, including mucus that can capture the virus and tiny hairs that move the mucus out of your body (2).

Even when these defences fail, your body still has some other options left. When a virus enters one of your cells, the cell recognises it as an invader within minutes and initiates a cascade of chemical signals to mobilise its defences (2). Some of those chemicals turn your defences up or down and some signal to neighbouring cells to start similar defence responses (2). Others damage the virus itself (2). If that’s not enough to kill the virus, then sometimes the cell self-destructs to prevent the virus from further spreading (2).

Remember we said above that an infected cell can send chemical signals to mobilise your defences? Some of those signals attract white blood cells, known as T-cells (2). These T-cells can trace, bind to and kill infected cells, which will then stop the flu virus from spreading.

In fact, your body has a number of different types of white blood cells, including B-cells as well as T-cells. B-cells produce antibodies, which neutralise viruses (1), amongst other things.

Once T-cells and B-cells have been triggered a first time to respond to a specific virus, they will remember that virus throughout your life (2). This memory allows your T-cells and B-cells to respond immediately each time that same virus tries to infect you again (2).

Keeping your immune system is vital for fighting the flu, so take care to feed it well and keep it fit.


Sources
(1) https://www.nobelprize.org/nobel_prizes/medicine/laureates/1996/illpres/introduction.html
(2) https://wiki.ecdc.europa.eu/fem/w/wiki/applied-immunology

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