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As the pandemic continues - variants[br]have become the latest concern

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with notable examples detected [br]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 [br]of a collection of mutations,

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

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So what do scientists mean when they talk[br]about variants

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and what might this mean [br]for the future of the pandemic?

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Viruses multiply by copying [br]their genomes over and over.

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

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Each of these imperfect copies [br]is a variant.

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

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

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

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

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The more a virus is allowed [br]to replicate unchecked,

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

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

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

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such as people with compromised[br]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 [br]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[br]to label it a ‘variant of concern’,

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

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For months, scientists [br]have been striving to work out

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

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Because a variant spreading [br]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 [br]could, by chance,

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move a variant [br]from one region to another,

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like tourists travelling back[br]from popular vacation spots.

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

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

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This is called[br]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 [br]and trace new variants

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and flag new or worrying [br]patterns of infection.

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Meanwhile lab studies [br]can start to pinpoint

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how the mutations are changing [br]the properties of the virus.

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And studies like these [br]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,[br]and there are hints that certain mutations

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

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

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

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It affects the spike protein

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that coronavirus particles [br]use to penetrate cells.

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

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and makes the new variant [br]more infectious than the original virus.

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N501Y also known as Nelly, [br]is another spike protein mutation

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which appears to be associated [br]with increased transmissibility.

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

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and P.1 strains – [br]all variants of concern.

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

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with another spike protein mutation, [br]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 [br]in South Africa and Brazil.

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Lab studies in early in 2021 [br]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 [br]the efficacy of several vaccines.

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Despite these worries, the coronavirus [br]is actually mutating very slowly

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compared to something like influenza

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and it seems like the vaccines [br]developed so far

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will remain at least partly effective.

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

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

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Firstly, to do anything [br]researchers need data.

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It’s very important to monitor and trace [br]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 [br]Genomics UK consortium, or COG-UK,

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have stepped up their efforts [br]to combine fast sequencing

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with efficient data sharing.

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

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Next, researchers need to look forward [br]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 [br]are also being tested

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but it could be difficult to perform [br]reliable clinical trials

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amid the ongoing vaccination programmes.

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

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Public health policies [br]such as track and trace,

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social distancing and vaccine roll-outs

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are powerful tools [br]to interrupt transmission

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and keep tabs on new variants.

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After all, every time the virus [br]is prevented from spreading,

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it's also prevented from mutating,

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