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

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with notable examples detected in South Africa,[br]Brazil and the UK.

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But variants are complicated. Each one is[br]made up of a collection of mutations,

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all of which have the potential to change the[br]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 for the future of the pandemic?

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Viruses multiply by copying their genomes[br]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[br]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 change the virus[br]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 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[br]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[br]from medical treatment or those who are HIV+.

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If a particular set of mutations makes a variant[br]more successful, 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[br]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[br]to work out what’s changed in these variants,

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and what those changes mean.

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Because a variant spreading doesn’t necessarily[br]mean that it has an advantageous mutation.

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For example a small number of people could,[br]by chance, move a variant from one region

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to another, 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 requires[br]a combination of studies.

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Epidemiology can help detect and trace new variants and flag[br]new or worrying patterns of infection.

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Meanwhile lab studies can start to pinpoint how the[br]mutations are changing the properties of the virus.

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And studies like these are starting to identify[br]mutations 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 natural[br]and vaccine derived immunity.

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

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

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It affects the spike protein that coronavirus[br]particles use to penetrate cells. A mutation

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

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This mutation has been detected in the B.1.1.7, [br]B.1.351 and P.1 strains - all variants of concern.

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The worry of so-called ‘immune escape’ has also been hinted at with another spike protein mutation, E484K or Eek.

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Eek has been spotted in B.1.351 and P.1, the[br]variants detected in South Africa and Brazil.

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Lab studies in early in 2021 showed that the[br]variant could evade some virus-blocking antibodies,

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while trials in South Africa suggested that[br]the variant reduced the efficacy of several vaccines.

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

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something like influenza and it seems like[br]the vaccines developed so far 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 researchers need data

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- it’s very important to monitor and trace the emergence of [br]variants and that isn’t always simple to do.

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

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have stepped up their efforts to combine [br]fast sequencing 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[br]how these mutated viruses could affect global

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vaccination efforts. Existing vaccines can be redesigned and[br]combinations of vaccines are also being tested

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but it could be difficult to perform reliable [br]clinical trials amid the ongoing vaccination programmes.

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

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Public health policies such as track and trace, social distancing and vaccine roll-outs

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are powerful tools to interrupt transmission and keep tabs on new variants.

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