Kovach 19 myths have spread just about
as quickly as the disease itself but one
myth in particular just won't go away
that Tsarskoe v2 the virus that causes
Kovac 19 isn't naturally occurring and
was actually man-made in fact one
substantial survey found that almost 30
percent of Americans believe that this
virus came from a lab but scientists
believe that they can confidently say
that the virus wasn't created by humans
and the myth going around is nothing
more than that a myth so how do they
know with such certainty the key is in
the virus's genetic code this is the
genomic sequence for Tsarskoe v2 it was
decoded in January 2020 just weeks after
the world started to learn of this novel
coronavirus each of those letters is a
genetic building block known as a
nucleotide and when built up they form
an organisms genetic code which we can
use to understand them each organism has
a different code and a varying amount of
nucleotides a human has about 3 billion
of them whereas a virus such as SARS CO
v2 has about 30,000 your genetic
sequence can give information about your
hair I color sex and lineage and just
like your genes give clues about who and
where you come from scientists can use a
virus genome sequence to help explain
where that virus originated as well an
ancestry test for viruses if you will we
honed in on the parts of the virus that
we thought were unique and it might play
a role in the evolution of the virus but
also in the pathogenesis of it
and a couple of things get out really
quickly when we started to pair with the
other viruses that had come before
that's Robert Geary a professor of
microbiology and immunology at Tulane
University along with his colleagues he
used the virus sequence to try and
understand where Tsarskoe v2 came from
they first looked at the viruses
backbone that's the whole genomic
structure unique to each virus like a
viral template simplified the backbone
for SARS Co v2 and it's 30,000
nucleotides looks a little bit like this
each section is responsible for a part
of the virus for example this one is
responsible for the Spike proteins you
may have seen lining the virus shell so
it may not come as a surprise that to
engineer a virus in a lab you would need
to start with a backbone but to
manufacture from scratch the backbone of
a virus that can also cause disease is
almost impossible I mean people just
don't know enough about what makes a
virus pathogenic to be able to assemble
that how do you pick all the
possibilities to get to that last little
bit that's going to turn it into the
worldwide pathogen which sequences you
think about to put in there
simply there's just not enough knowledge
about how to make a new virus that would
also cause significant devastation like
SARS Co v2 has so creating a new deadly
backbone is pretty much impossible but
there is another way the novel
coronavirus could have been created in a
lab and that would be using an existing
virus backbone or genetic sequence as a
starting point with a recycled backbone
two main methods could have been used to
create the new virus they could have
either quickly mutated it or added and
deleted parts of the existing virus but
additions and deletions and a virus
leave a trace that can be pointed out
pretty quickly a little bit like
removing a red brick from a wall and
replacing it with a black brick this is
exactly what magic bony an associate
professor at Penn State looked for you
might see an insertion that looks
unusual and you look out in nature and
you see that no other viruses have
genetic insertion like that we did not
see any genetic insertions that also
identified in nature so there's no
evidence suggesting
with man-made or laboratory created to
mountain so what if they went with the
other option and mutated an existing
virus this is known as serial passage
and acts in a similar way to selective
breeding scientists are able to mimic
evolution to a degree by forcing the
virus to mutate over and over again into
a potentially different form this can be
used to weaken a virus which is how some
vaccines have been made or to strengthen
a virus say by making it more
transmissible but for this to work the
existing virus would have to show
significant genetic similarity to the
new virus in fact they would have to be
almost identical because this process
only speeds up viral evolution and has a
limit it's not possible to direct
mutations into a completely different
form yet Gary and his team found that
the backbone for Tsarskoe v2 was
strictly unique differing significantly
from other corona viruses for example
Tsarskoe v the first SARS has only about
a 79% genetic sequence match to Tsarskoe
v2 so it's ruled out the best candidate
is our ATG 13 a bat coronavirus with a
96% gene sequence similarity 96% sounds
pretty close but in genetic terms that's
actually pretty long ways away to put it
in perspective humans and chimpanzees
share 99% at the same genome and you may
have noticed there's still a large
difference between the two for Tsarskoe
v2 and our ATG 13 that 4% is the
difference of about 800 nucleotides or
about 50 years of natural evolution 800
is too big a barrier you had something
that was 99.5% of 99.7% similar maybe
only 20 and 30 nucleotides you might get
away with it you might be able to
manufacture that but it just wouldn't be
possible with current knowledge and
existing viruses there's also another
part of the gene sequence that helped
Gary and his colleagues learn about the
natural origins of Tsarskoe v2 in
particular this set of nucleotides in
the gene sequence
you might remember those from earlier
they're responsible for the virus spike
proteins the pointy claw like arms
the outside of a virus that give it its
distinctive appearance and coronaviruses
their name specific viruses including
corona viruses use these arms to enter
and takeover host cells but this piece
of the spiked protein helped tell the
researchers that this virus originated
in nature this set of nucleotides
relates to the receptor binding domain
or RBD that's the part that latches on
to the receptors on targeted cells as
viruses can only survive when inside
other cells this is a vital section that
you would have to focus on if you were
to make a virus in a lab Gary Anna's
team found the RBD has evolved
specifically to bind to the human cell a
ce2 a receptor usually used to help
regulate blood pressure but it's the way
it so successfully binds to the AC e2
receptor that is crucial
you see when a scientist tests what
aspects would make a virus more potent
they run models through computer
simulations but when researchers put
this sequence through those simulations
they found that Tsarskoe v2s RBD
shouldn't be successful at all and would
actually cause poor efficiency and
transmission which we know is not the
case yeah by working in the lab working
at the computer trying to figure it out
I mean they just went down and come up
with this particular way to have this
virus buying good receptor a very
important part of the whole replication
process in other words if your goal was
to make a virus to infect humans you
wouldn't have chosen this one basically
what nature isn't a solution for binding
that is better than any computer and
ultimately better than what any
scientist would so we know why
scientists confidently say Tsarskoe v2
wasn't made in a lab but that's not the
end of the story
it's also been rumored that Tsarskoe v2
was a known virus that was accidentally
leaked from a lab now we can't say for
certain this isn't the case but it's
highly unlikely for one this virus
wasn't sequenced before January 2020 and
if it was the world would know because
the Wuhan Institute of ayala G was
specifically looking for something like
this in order to protect the world from
any outbreaks sorry
Khurana buyers that with 76% similar to
the original guitars one I mean they
would have published that as fast as
they could that would have been at least
in the scientific world big news but
it's also just statistically highly
unlikely so just that in nature there
means the people that are having
millions of encounters with these
animals and you know we're talking about
a handful of you designate in the whole
world scientists that go out and track
that so just on the awesome of things
it's just a miniscule chance that it was
was one scientist that accidentally
infected himself and that's very
sophisticated laboratory setting so
Tsarskoe v2 s origin is no longer a
mystery but where and how it jumped in
nature well that's a question many are
still trying to answer