Kind: captions
Language: en
[Music]
new coronavirus variants are making
covid19
more transmissible why basically
inside the bodies of people who are
infected the coronavirus
is mutating and evolving viruses
you're making billions upon billions of
new copies
and you're getting so many generations
of the virus that it's much
easier for viruses to evolve and adapt
over time
now this coronavirus mutates slowly
compared to other kinds of viruses like
the flu or
hiv on average only two new mutations a
month worldwide
the virus basically jumps from one
person to the other without changing
because it's so quick it infects cells
very quickly it makes copies very
quickly
even before the immune system has had a
chance to put any pressure on the virus
it's already gone
and infected somebody else this virus
unfortunately has a proofreading
mechanism
however it does accumulate mutation over
time
and in certain people who harbor the
virus for long periods of time
weeks or months you get more of these
mutations stacking up
many of those individuals have immune
deficiency problems their immune system
doesn't work
very well and so they can't clear the
virus generating more and more mutations
and though some of these people don't
display symptoms
they shed lots of virus over the course
of their lengthy infections
those isolated events are spilling out
into the community and now leading to
large numbers of new infections
take variant b117 first documented in
the uk
we were one of the groups that
discovered it there were eight spike
mutations
meaning mutations in the genes that make
the protein that forms the coronavirus's
distinctive
spikes which cover its outer surface and
dock to the cells in our body
these mutations allow it to bind more
tightly
to the h2 receptor that's on the human
cell which
appears to allow it to replicate more
efficiently as well
all proteins including the spike protein
are built from subunits called
amino acids of the eight changes in each
piece of this variant spike protein
two are deletions of a single amino acid
and
six are amino acid substitutions
these different components change the
shape of the spike protein slightly
which appear to make it easier for the
coronavirus to invade a human cell
as a result the uk variant is about 50
more transmissible than the original
version due
it seems in large part to one of these
substitutions
in just a span of a few weeks it's
overtaken all the other circulating
strains in the uk
it's a competition right between that
new variant
and the variance that's already present
in the community the amount of virus in
the nose
appears to be higher in people with the
new variant as compared to other strains
and that explains potentially why we are
seeing higher transmission rates
in other words a person infected with
this variant might be exhaling or
expelling
more virus meaning anyone breathing the
same
air would be more likely to get infected
that is
a major concern because that means
virus can spread more quickly amongst
the population
experts are concerned that the uk
variant may spread quickly
outside the uk including in the u.s
there are other variants that have
emerged as well one in brazil
another in south africa both share one
of the uk variants spike mutations
and both appear more transmissible than
the original version
across these variants additional
mutations may help the coronavirus
evade the antibodies developed by our
immune systems
in response to older versions of the
virus while other mutations might make
the new strains
even more infectious the fact that these
strains are more transmissible
also means that we need to do an even
better job adhering to all of the public
health interventions
a new variant has also emerged in
california these aren't the first
examples of a covit 19 variant replacing
an earlier version of the virus
last spring the d614g variant emerged
and replicated more efficiently than the
original wuhan version this
variant quickly spread worldwide and
became the dominant strain
so we've already seen it happen once
with this virus but this time we've got
vaccines
a sars kobe 2 strain that can escape
from a vaccine would be a disaster
the vaccines still appear to work
against the uk variant
but the variants from south africa and
brazil are more concerning
the vaccines may be less effective
against them since the vaccines trigger
the production of antibodies
custom made to fight an earlier version
of the virus
if the vaccine doesn't elicit enough of
an immune response
that those variants may not be as well
covered
by the vaccine the variants are probably
going to lead to small increases in the
number of vaccine failures
but the question is how big is that jump
and i think that's the thing we don't
know yet
the variants make the need for
widespread vaccination even more urgent
experts want fewer opportunities for
these variants to find their way back
to people with compromised immune
systems where they could mutate further
becoming super variants the pfizer
biontec
and moderna vaccines both rely on
messenger rna
a bit of genetic material that codes for
the coronavirus spike protein
when it's injected into our bodies our
immune system learns to recognize a
piece of the virus
so that if the real thing ever infects
us we've already got the weaponry to
fight it off
the current vaccines contain the rna
sequence of the original coronavirus
spike protein
but one advantage of using rna is you
can just update the vaccine with the
sequence of the new
mutated spike protein both vaccine
makers are working to do just
this by developing an additional booster
shot
i do worry about having to do you know
sort of catch up
with the vaccine one way to keep up with
covet and fight it off is to ramp up our
surveillance
by sequencing the virus that is reading
out its genetic signature
to identify mutations and new variants
as they emerge
yes if we do it right we'll stay ahead
of the virus so we'll see these things
popping up
right now i would say that we're largely
blind in this country
we're not doing a sufficient job of
monitoring all of the viral variants and
figuring out why the outbreak is so out
of control
in certain regions of the of the country
tracking these variants more closely
will also help keep our testing up to
date so we can actively detect the
coronavirus strains in circulation
as more and more people are vaccinated
infections are expected to drop
gradually but we're racing against a
fleet of increasingly transmissible
coronavirus variants
so we need to we need to get a move on
if we can get people vaccinated i think
that's the fastest way out of this
this nightmare