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