ever since the coronavirus outbreak began we've all had a lot of questions where did the virus
come from how does it spread how infectious is it and is it mutating to become more contagious well
today we're going to clear up perhaps the biggest question of all if this virus is mutating what
does it mean for us but first let's just make sure that we're all on the same page about mutation
mutations are essentially changes to an organism's genetic material that can happen at any phase of
life they can happen for a whole host of reasons like if dna or rna does a sloppy job at copying
itself during cell division or if an organism is exposed to damaging environmental factors
such as smog or uv light mutations can affect any aspect of an organism's life from its appearance
to its behavior or they can have absolutely no effect at all and while mutation rates
are naturally higher in viruses than say humans mutations are in fact absolutely essential to the
evolution of all life forms so the term mutation i think has lots of connotations but mutation
itself you can just think of it really as being a change and that's all it is it's a small change in
the genome at a certain position in the genome and all organisms mutate it's not a surprise
that we have a virus that is mutating in fact that's absolutely normal mutations are generally
really simple things an a and the virus's genetic code might change to a t or a g to a c
these letters specify particular nucleotides or bases in a gene at some point early on in the
pandemic one of the viruses 30 000 letters jumped resulting in a protein d to g change creating a
mutation in a paper published in early 2020 a team from the los alamos national laboratory suggested
that this mutation was causing sar cov2 to be more contagious by allowing the virus to enter cells
more efficiently d614g is probably the most famous mutation in the sars cog2 genome it
was really the first one that people picked up as potentially interesting and then since then
there's really been an explosion of studies to try and understand what this mutation might do
there's currently no strong or good evidence that this mutation changes the severity of disease or
really affects how the disease manifests itself when it was first reported in march this mutation
was only found in a few of the genetic sequences that were available to scientists at the time and
was mostly present in europe but by april it was present in over half of the available sequences
and had expanded globally today this mutation is so widespread that it isn't just a deviation
from the pandemic it is the pandemic luck is really an important contribution it's not
inconceivable that we had a subset of the viral population that was for example introduced into
europe or eurasia where we really had very few interventions in place that pocket of viruses
expanded very happily and readily until we had for example lockdowns we should also keep in mind that
this mutation is not found on its own so it's found with three others almost 100 of the time
and so this is quite consistent with the idea that we might have this ancestral virus that happens to
have these four mutations it gets introduced to regions of the world it proliferates and actually
we see these mutations at really very high frequency if we look at stars cos2 now around the
world maybe 80 of them actually carry this set of four mutations and so we certainly can't ignore it
so are these mutations just par for the course or are they contributing to the emergence of entirely
new strains different from the original one that first left wuhan in 2019 well this is where
things get a little murky there's still no clear evidence that sar cov2 has evolved into forms that
are significantly different from the dominant strain that we're familiar with in fact there's
no real consensus in the scientific community on how many strains of the coronavirus even exist
or even if more than one strain exists at all and the reason for that might be because there's
no universally accepted definition for strain to begin with generally we would use the word
strain where we see marked differences between pathogens based on their functional behavior
that's not what we see in sars cog2 if we look at the genomic diversity of this particular virus
it's still really very low so low that if you took a sample from an infected patient in china
and a sample from someone in the u.s those samples would be different only by a handful
of changes although those changes might still provide information about how the virus transmits
which leads us to the final question what does this mutation mean for us we need to
be very aware of the regions that our vaccines or antibody therapies are targeting the vast
majority of these are targeting the spike protein and so we particularly are looking for mutations
in that region d614g falls slightly outside of what we would call the the most important region
of the spike protein at the same time any of these mutations which have been observed in this region
are still really at very low frequency and this gives us plenty of opportunity to characterize
their potential impact for now we watch we relate and we monitor any lingering questions
about mutation and its potential effects on future covin 19 treatments or do you have any
other coven 19 related stories that you want to see us cover let us know down in the comments
make sure to subscribe to seeker for more coven 19 coverage and as always thank you so much for
watching you