Coronavirus Variants: What you need to know

As the global COVID-19 pandemic continues - viral variants have become the latest concern

But variants are complicated. Each one is made up of a collection of mutations, all of which have the potential to change the SARS-CoV-2 virus in unexpected ways.

So what do scientists mean when they talk about variants and what might this mean for the future of the pandemic?

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As the pandemic continues, variants
have become the latest concern,

with notable examples
detected in South Africa,

Brazil and the UK.

But variants are complicated.

Each one is made up
of a collection of mutations,

all of which have the potential
to change the SARS-CoV-2 virus

in unexpected ways.

So what do scientists mean
when they talk about variants?

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

Viruses multiply by copying
their genomes over and over.

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

Each of these imperfect copies
is a variant.

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

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

But very rarely, mutations
can change the virus

in some important ways.

It could become more infectious,

or more able to avoid the immune system.

The more a virus is allowed
to replicate unchecked,

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

That can occur when viruses

are allowed to spread quickly
through a population,

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

such as people with compromised
immune systems from medical treatment

or those who are HIV+.

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

it might become more prominent than others

and that’s when it gets noticed.

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

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

For months, scientists
have been striving to work out

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

Because a variant spreading
doesn’t necessarily mean

that it has an advantageous mutation.

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

move a variant from one region to another,

like tourists travelling back
from popular vacation spots.

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

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

This is called the founder effect.

Understanding why a variant has emerged

requires a combination of studies.

Epidemiology can help detect
and trace new variants

and flag new or worrying
patterns of infection.

Meanwhile, lab studies
can start to pinpoint

how the mutations are changing
the properties of the virus.

And studies like these
are starting to identify mutations

that have given the virus an upper hand.

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

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

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

spread widely
in the early days of the pandemic

and can be seen in almost all variants.

It affects the spike protein

that coronavirus particles
use to penetrate cells.

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

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

N501Y, also known as Nelly,
is another spike protein mutation

which appears to be associated
with increased transmissibility.

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

and P.1 strains-- all variants of concern.

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

with another spike protein mutation:
E484K or Eek.

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

the variants detected
in South Africa and Brazil.

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

some virus-blocking antibodies,

while trials in South Africa suggested

that the variant reduced
the efficacy of several vaccines.

Despite these worries, the coronavirus
is actually mutating very slowly

compared to something like influenza,

and it seems like the vaccines
developed so far

will remain at least partly effective.

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

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

Firstly, to do anything,
researchers need data.

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

and that isn’t always simple to do.

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

have stepped up their efforts
to combine fast sequencing

with efficient data sharing.

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

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

could affect global vaccination efforts.

Existing vaccines can be redesigned

and combinations of vaccines
are also being tested,

but it could be difficult
to perform reliable clinical trials

amid the ongoing vaccination programmes.

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

Public health policies,
such as track and trace,

social distancing and vaccine roll-outs

are powerful tools
to interrupt transmission

and keep tabs on new variants.

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

it's also prevented from mutating,

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

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