Lesson video

In progress...


Hello, I'm Mr. Whitehead and welcome to the RSHE health and prevention, basic health unit.

This lesson, we're going to look in at the immune system and how it works to fight off bacteria and infection.

Okay, let's get started with the lesson.

To successfully complete this lesson, you will need to following items. Piece of paper or a note pad, and a pen or a pencil.

There are a few tasks that you will require to complete during this lesson.

And there might be some notes that you want to jot down to show your teacher or to help you with some of the tasks.

Okay, let's have a look at the agenda of this lesson.

So first of all, you should have completed the intro quiz and hopefully, you got full marks on that quiz.

Don't worry if you didn't.

We're then going to look at some key words.

We'll then look at the white blood cells which are also known as our little warriors.

And we will look then at how our body responds to antigens and how our white blood cells responds to them.

And finally, once we've completed this lesson, you will complete the exit quiz.

Now let's take a look at some key words that you will need to know for this lesson.

So the immune system consists of many paths that work together to defend the body against defenders.

Pathogens are substances from the environment that our body does not recognise.

And antigens are substances left by pathogens which initiate an immune response.

Okay, let's take a look closely at the difference between pathogens and antigens.

So, pathogens are substances from the environment that our body does not recognise.

So as you can see on the image on the screen, the pathogen is the thing that enters the body, and that's the larger infection or bacteria that will enter the body, whereas the antigen are the little yellow dots which are just substances left behind as the pathogen moves through the body.


In a moment, I'm going to ask you to pause the video and write down some notes into relation to this question.

So what do you think our immune system defends against? So what does it fight against in the process in our body? What can it stop happening to our body? Okay.

Pause the video now, get some ideas down and then we'll come back and get some ideas I've come up with.

Welcome back.

So let's take a look at some things that our immune system defends against.

So first of all, our immune system defends against viruses, bacteria and cancerous cells.

There are plenty others that our immune system fights off against, but these are the main three that I've come up with for this lesson.


We're now going to look at some information on white blood cells, which are also known as our little warriors.

So white blood cells are known as the army of our bodies as they fight off harmful substances known as pathogens which can lead to viruses and illnesses, infections which can harm our bodies.

White blood cells only make up 1% of our blood.

So in reality, there's not a lot of our blood, which are white blood cells.

Our white blood cells can be increased by consuming more vitamin C such as foods like oranges.

Okay, let's take a look at this statement.

Or you're going to decide whether you think it is true or false.

White blood cells are super important to our bodies.

Is that true or is that false? Giving you a few seconds to think of the answer.

If you need, to pause the video and return once you've come up with an answer.

Welcome back.


Let's take a look at the answer to this statement.

So I asked you, white blood cells are super important to our bodies.

Is that true, or is that false? And the answer, is true.

They fight off harmful substances to keep our bodies healthy.

We're now going to to look at the difference between a non specific and specific responses to antigens.

So these are the two stages and barriers to our body that can stop any bacteria, pathogens and viruses from entering our body.

And what it does if it does enter our body.

So first non-specific response is how the body responds to generic bacteria, viruses and pathogens.

And this is the initial barrier in our body.

And this can be known as skin, small hairs in our lungs and mucus.

So as they try to enter our body, the bacteria, the virus and the pathogens, these are examples of parts of our body that will try and prevent them getting in.

And they're constantly patrolling our body waiting for any antigens that are trying to harm our body.

And they will fight them as soon as they try and enter our body, our white blood cells will send a non-specific response to try and break them down.

A specific response is how the body responds to specific pathogens.

And this is the second line of the defence.

And this can be seen through swelling and redness.

And these are triggered by antigens.

So as the body notices that antigens are being left behind by the pathogens, they will attack you go and find the antigen or pathogen and destroy them, as quickly as they come.


Based on that information, we're now going to answer this question.

The initial response to a pathogen is called, an antigen, a non-specific, antibody or specific? Okay.

Let me give you a few seconds to think about this question before we look at the answer.


Let's take a look at the answer.

And the answer is, non-specific response is the initial response to any pathogens entering our body.

Well done if you got that one right.

We're now going to look at how antibodies work within our body.

So first of all, antibodies are the memory cells of our body.

And they work by detecting all pathogens, viruses, and bacteria that may have already entered our body previously.

So antibodies attempt to latch onto the antigens.

So they will notice, and they will recognise if the antigen has been in the body before.

And if they have, they make a specific cell that can latch straight onto the antigen, making it easier to destroy and get rid of that harmful antigen that just entered our body.

Antibodies know how certain antigens work, making it easier to remove.

So because they know them and they remember them from last time.

They know how they work, they know how they move on their body, so they can attack them nice and quickly before they manage to get to other parts of the body and cause any harm to us.

Because actually antibodies that are potent of vaccines to prevent those getting ill from certain new infections and bacterias.

Take a look at this video to have a look how this works.

After we've been exposed to an infection, our immune system remembers the threat in particular by producing antibodies.

These are proteins that circulate in the blood and throughout the body.

They quickly recognise and disable the invader upon contact thereby preventing or minimising illness.

This is why we usually do not get sick with the same bug twice.

We are immune.

Vaccines mimic this process.

Encouraging immune system to make antibodies without us having to go through the illness.

Some of the leading cells vaccine candidates are mRNA vaccines.

Based on incorporating the genetic blueprint for the key spike protein on the virus surface into a formula that when injected into humans, instructs our own cells to make the spike protein.

In turn, the body then makes antibodies against the spike protein, and they protect us against viral infection.

This strategy is faster than all traditional approaches which often involve generating weakened or inactivated forms of the live virus or making large amounts of the spike protein to determine whether they can prompt an antibody response.

Once a potential vaccine is discovered, a number of checkpoints exist before it can be administered to people.

First, a preclinical tests, which involve experiments in a laboratory and with animals.

Scientists must ensure the vaccine candidate is not only effective, but also safe.

For example, an antibody response to an imperfect vaccine could, under extremely rare circumstances, end up increasing the danger of becoming infected.

When the potential vaccine achieves the necessary preclinical results, clinical trials can begin in a small group of people as the vaccine candidate advances, it is tested on increasing numbers of people with scientists and doctors, closely monitoring safety, efficacy, and dosing.

Upon successful completion of clinical trials, the vaccine candidate must be reviewed and approved by regulatory agencies, such as the FDA.

Before large-scale manufacturing and distribution gets underway.

And the licenced vaccine is administered widely.

Your ultimate task, before you complete your exit quiz is to create a mind map on the process of our body killing harmful pathogens.

Some things that you may want to include are the examples of pathogens.

So different examples of what pathogens are.

The non specific and specific responses.

So knowing the difference between them too.

Antibodies and what they do and how vaccines work with antibodies.

And diagrams and illustrations to help fully understand what we have done today.

To give you some more information on how antibodies work, you may want to conduct your own research using Google.

The NHS website has some useful information on that.

The World Health Organisation also has some great resources and information that you may want to use for your mind map.


Now you need to pause the video and complete your mind map.

Once you've completed your mind map, resume the video and we will complete the lesson.

Thank you so much for engaging so well in the lesson today.

I hope you have enjoyed it.

And I hope you've learned a lot about how our body fights off infections.

If you would like to, please ask your parent or carer to share your work on Twitter, tagging @ OakNational and #LearnwithOak.

I'm Mr. Whitehead, and I hope to see you all again soon.

Take care.