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Developing vaccines is usually a very lengthy
process.

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Taking, on average, 8 years to get approved.

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Since a few years, we have the ability to
create mRNA vaccines which can be developed

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much faster.

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So how do these vaccines work?

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Are they safe?

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And, how do they compare to traditional ones?

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But first, you must understand how the immune
system works.

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When a virus enters your body, it will attach
itself to one of your cells and inject its

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DNA or RNA into it.

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This is like a blueprint for your cells: containing
instructions on what the cell has to make.

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So, in this case, the virus's RNA will tell
your cell to make more copies of the same

0:00:39.250,0:00:40.490
virus.

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They become virus factories, pumping out new
copies of the virus that can infect even more

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cells.

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Naturally, our bodies have a defense system
for foreign intruders.

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The immune system attacks any protein, virus,
or bacteria that do not belong in our bodies.

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But it takes a few days for it to learn how
to attack the intruder.

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Meanwhile, the virus factories are running
non-stop, quickly replicating the virus and

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spreading it in your body.

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In other words: you start experiencing symptoms
of whatever has infected you.

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After a few days, however, your immune system
has figured out how to attack the virus and

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will start to produce antibodies.

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These attach themselves to the virus, preventing
them from infecting more cells and marking

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them for destruction.

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As you can see, the immune system is remarkable,
but it's also slow to mount an attack.

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That's the reason why we get sick in the first
place.

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So to give it a helping hand, we developed
vaccines.

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The main idea is to train your immune system
to recognize and fight off an infection before

0:01:42.200,0:01:43.860
it has occurred.

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Almost like showing your immune system a mug
shot of the virus and saying: "if you see

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this, kill it."

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There are various types of vaccines, but let's
take a look at mRNA vaccines, the new kid

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on the block.

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To understand how they work, let's take the
COVID19 pandemic as an example.

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You might have seen pictures of the virus,
with its distinctive spikes.

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These spikes allow the virus to attach to
specific cells in your body (ACE2) and infect

0:02:10.099,0:02:11.099
them.

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Now here's the key idea for the COVID19 vaccine:
what if we could train our immune system to

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recognize these spikes by having our body
produce them?

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To do that, researchers took the virus's blueprint,
its RNA, and isolated the part responsible

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for producing the spikes.

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Armed with this blueprint, they created mRNA
or messenger RNA.

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This is a special form of RNA that can enter
your cells and give them instructions.

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In this case, the RNA contains instructions
to build the spikes of the coronavirus, not

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the virus itself, just the spikes.

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So mRNA vaccines contain instructions for
your cells that tell them to build a part

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of a virus in large volumes, almost like giving
them a recipe to follow.

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Once this is happening, your immune system
kicks into action and start learning how to

0:03:01.310,0:03:02.860
attack these intruders.

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Again, it takes time for the immune system
to fight off these spikes, but you won't get

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sick because it's only the spikes, not the
virus itself.

0:03:12.190,0:03:13.190
And that's it!

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Your immune system has learned how to attack
the spikes of the coronavirus.

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It destroys all the spikes and even breaks
down the mRNA vaccine itself.

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The only thing left in your body are special
"B cells" or memory cells.

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These can linger around for months or years
until the same virus infects you again.

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When that happens, the B cell can produce
the correct antibodies right away, preventing

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the virus from spreading and making you sick.

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What's interesting about this mRNA technique
is that it's relatively quick to develop a

0:03:43.760,0:03:48.540
vaccine as soon as we know the DNA or RNA
sequence of a virus.

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And secondly, because the vaccine only makes
our body produce a part of a virus, we can't

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get sick.

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More traditional vaccines use weakened versions
of the actual virus.

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This also triggers an immune response but
could also give you mild symptoms.

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Now you know how mRNA vaccines work, what
about their safety?

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The biggest misunderstanding about this technology
is that the mRNA in the vaccine can enter

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our cells and changes our very own DNA.

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But that's not true.

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mRNA is very fragile and only survives a few
hours in our bodies.

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Just long enough to produce viral proteins,
like the spike, and kickstart your body's

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immune response.

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After a while, your body will break down all
of the vaccine's mRNA.

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Another misconception is that they're unsafe
because they were developed so quickly.

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In the case of COVID19, it only took a few
days to a first test vaccine.

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It was this fast because some companies have
invested a lot in mRNA technology and because

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we already knew a lot about the family of
coronaviruses.

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But that's it for this video.

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Now you know how mRNA vaccines work.

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But don't take my word for it!

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All sources used to make this video are listed
in the description below.

0:05:04.620,0:05:08.199
Check it out if you want a more in-depth explanation.

0:05:08.199,0:05:11.849
Give this video a thumbs up if you found it
interesting and consider subscribing to the

0:05:11.849,0:05:12.849
channel.

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Thanks for watching, and till next time!