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Recently there has been
a lot of talk about measles.
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What does measles actually do,
and should you vaccinate against it?
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Or is this just hysteria?
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Measles is a virus:
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a hull of proteins, RNA,
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plus some more proteins for reproduction.
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It cannot reproduce by itself;
it needs a host cell to do so.
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To understand measles, we have to
understand the immune system.
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You might already have seen
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the visual system we developed
to help here.
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Now, let’s focus on the parts of
the immune system relevant to measles.
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The measles virus enters humans
through the nose, mouth, or eyes.
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The measles infection starts in the lungs.
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Measles is especially good at infecting
the body’s first line of defence:
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macrophages, powerful guard cells
that protect the lungs from intruders.
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They enter a cell and take it over.
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The virus reprograms the cell and
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transforms it into a dangerous
virus production center.
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Once a cell is filled with viruses,
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they leave the crippled cell
and begin the cycle over again.
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But the immune system has
powerful weapons against virus infections:
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natural killer cells.
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These cells basically patrol the body
and check other cells for infections.
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If they find an infected cell,
they order it to commit suicide.
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This is so effective that for
the first 10 days or so,
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you will not even notice that
you’re infected with measles.
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And now, the reason why measles
is so powerful.
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After a period of fighting and dying,
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macrophages alert the brain of the
immune system:
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the dendritic cells.
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The job of the dendritic cells is
to collect samples of intruders,
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travel to the lymph nodes,
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and then activate the heavy weapons
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that eradicate the infection very fast
in a team effort.
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But the measles virus uses
a dreadful tactic.
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It infects the dendritic cells
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and uses them as a Trojan horse
to enter deeper into the body.
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The infected cells travel to the next
lymph node
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to alert other immune cells.
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Once it arrives,
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the measles virus spreads around the
virgin T and B cells
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and infects them.
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It attacks the very system that
evolved to fight it.
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Now, things happen very fast.
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The lymph system spreads the virus
everywhere
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and it enters the bloodstream,
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infecting cells while traveling.
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Measles infects organs like
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the spleen, the liver, the intestines,
and, most importantly, the lungs.
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The symptoms range from
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a very high fever, headache, sickness,
bronchitis, and, of course, a rash.
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In the lungs, the immune system was
doing pretty okay.
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But now, millions of viruses
attack a second time
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and kill countless cells, wiping out
the defense systems.
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In this phase, you start coughing out
millions of measles viruses.
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Measles is so contagious at this stage,
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that if you meet someone
who isn’t vaccinated,
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there’s about a 90% chance
you’ll infect them.
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Without the protective army in the lungs,
other bacteria or viruses that
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would usually not stand a chance can
now enter the lungs and develop into
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harmful parallel infections that
can cause pneumonia,
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the most common way to
die from measles.
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Your body’s immune system is now
seriously wounded.
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Various protective systems are hurt
and disrupted.
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The virus spreads everywhere, infecting
the skin all over the body.
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The typical measles rash now
becomes visible.
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And in some cases, the measles virus
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reaches the brain and causes
a brain infection.
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If it does so, the chances of dying
are between 20 to 40 percent,
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and there may be long-term damage.
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But your body is far from giving
up at this stage,
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and it fights back agressively.
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Some dendritic cells survive
long enough to activate
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the anti-virus forces of the body.
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Plasma cells in the lymph nodes
start producing billions of antibodies,
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tiny proteins that mark infected cells
for destruction
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or clump the virus together.
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Killer T cells flood the body
and kill infected cells left and right.
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After 2 to 3 weeks, the body usually gets
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the upper hand and overwhelms
the infection.
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But the immune system is now
seriously weakened,
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and may take weeks or months to recover,
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leaving the body vulnerable
to other diseases.
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But, if you make it, you are now immune:
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the immune system remembers
the virus forever.
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Measles is no joke.
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Although 84% of all humans are
vaccinated against measles,
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122,000 people died because
of the infection in 2014.
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Some people cannot get vaccinations,
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either because they’re too young,
because of chemotherapy or HIV,
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or because they’re allergic
to the vaccine.
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They need the rest of us to
stop the disease for them.
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The measles vaccination is
safe, cheap, and available.
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There are no benifits from having
measles at all.
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You don’t strengthen your immune
system and it’s not more natural.
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Most people who don’t vaccinate
only want the best for their children,
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which is honorable.
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But if you ask yourself,
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“Am I putting the life of my child
and other children at risk by
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not vaccinating against measles?”
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The sad answer is yes. Yes, you are.
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Let’s not play the blame game, though.
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Let’s work together and
eradicate this virus.
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Together, we can get rid of these
dreadful monsters and
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consign them to their rightful place:
the history books.