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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
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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
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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
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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
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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.
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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
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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.
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Check it out if you want a more in-depth explanation.
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Give this video a thumbs up if you found it
interesting and consider subscribing to the
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channel.
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Thanks for watching, and till next time!