WEBVTT

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As the pandemic continues - variants
have become the latest concern

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with notable examples detected 
in South Africa,

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Brazil and the UK.

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But variants are complicated.

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Each one is made up 
of a collection of mutations,

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all of which have the potential to change 
the SARS-CoV-2 virus in unexpected ways.

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So what do scientists mean when they talk
about variants

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and what might this mean 
for the future of the pandemic?

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Viruses multiply by copying 
their genomes over and over.

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But like an old photocopier, 
these copies aren’t always perfect.

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Each of these imperfect copies 
is a variant.

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Normally the imperfections or mutations 
don’t change how the virus behaves

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and they can often make it less successful
than the original strain.

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But very rarely mutations can 
change the virus in some important ways.

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It could become more infectious,
or more able to avoid the immune system.

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The more a virus is allowed 
to replicate unchecked,

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the more chance it has to accumulate 
these rare beneficial mutations.

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That can occur when viruses are allowed
to spread quickly through a population,

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or if they encounter a host 
that’s less able to fight them,

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such as people with compromised
immune systems from medical treatment

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or those who are HIV+.

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If a particular set of mutations makes 
a variant more successful,

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it might become more prominent than others

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and that’s when it gets noticed.

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Epidemiologists may even decide
to label it a ‘variant of concern’,

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like the examples identified in Brazil, 
South Africa and the UK.

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For months, scientists 
have been striving to work out

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what’s changed in these variants,
and what those changes mean.

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Because a variant spreading 
doesn’t necessarily mean

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that it has an advantageous mutation.

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For example a small number of people 
could, by chance,

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move a variant 
from one region to another,

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like tourists travelling back
from popular vacation spots.

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This could cause that variant to start
spreading in a new location

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even though there may be no significant
change to the biology of the virus.

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This is called
the Founder Effect.

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Understanding why a variant has emerged

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requires a combination of studies.

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Epidemiology can help detect 
and trace new variants

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and flag new or worrying 
patterns of infection.

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Meanwhile lab studies 
can start to pinpoint

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how the mutations are changing 
the properties of the virus.

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And studies like these 
are starting to identify mutations

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that have given the virus an upper hand.

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Some variants are faster spreading,
and there are hints that certain mutations

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could start to weaken or even evade 
natural and vaccine derived immunity.

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For example, the D614G mutation, known to
virologists as Doug, spread widely

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in the early days of the pandemic 
and can be seen in almost all variants.

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It affects the spike protein

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that coronavirus particles 
use to penetrate cells.

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A mutation in the genome changes 
one amino acid for another,

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and makes the new variant 
more infectious than the original virus.

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N501Y also known as Nelly, 
is another spike protein mutation

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which appears to be associated 
with increased transmissibility.

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This mutation has been detected
in the B.1.1.7, B.1.351

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and P.1 strains – 
all variants of concern.

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The worry of so-called ‘immune escape’ 
has also been hinted at

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with another spike protein mutation, 
E484K or Eek.

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Eek has been spotted in B.1.351 and P.1,

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the variants detected 
in South Africa and Brazil.

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Lab studies in early in 2021 
showed that the variant could evade

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some virus-blocking antibodies,

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while trials in South Africa suggested

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that the variant reduced 
the efficacy of several vaccines.

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Despite these worries, the coronavirus 
is actually mutating very slowly

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compared to something like influenza

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and it seems like the vaccines 
developed so far

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will remain at least partly effective.

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But scientists are still taking the threat
posed by variants seriously.

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And there are several things that 
can be done to help tackle it.

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Firstly, to do anything 
researchers need data.

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It’s very important to monitor and trace 
the emergence of variants

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and that isn’t always simple to do.

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Organisations like the COVID-19 
Genomics UK consortium, or COG-UK,

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have stepped up their efforts 
to combine fast sequencing

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with efficient data sharing.

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COG-UK has already sequenced 
over 400,000 SARS-CoV-2 genomes.

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Next, researchers need to look forward 
to how these mutated viruses

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could affect global vaccination efforts.

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Existing vaccines can be redesigned

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and combinations of vaccines 
are also being tested

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but it could be difficult to perform 
reliable clinical trials

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amid the ongoing vaccination programmes.

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Right now though, work needs 
to continue at a national level.

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Public health policies 
such as track and trace,

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social distancing and vaccine roll-outs

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are powerful tools 
to interrupt transmission

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and keep tabs on new variants.

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After all, every time the virus 
is prevented from spreading,

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it's also prevented from mutating,

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nipping new variants in the bud
before they even have a chance to develop.