0:00:00.299,0:00:05.130
As the pandemic continues - variants[br]have become the latest concern

0:00:05.130,0:00:07.823
with notable examples detected [br]in South Africa,

0:00:07.823,0:00:10.320
Brazil and the UK.

0:00:10.320,0:00:12.943
But variants are complicated.

0:00:12.943,0:00:15.735
Each one is made up [br]of a collection of mutations,

0:00:15.735,0:00:22.379
all of which have the potential to change [br]the SARS-CoV-2 virus in unexpected ways.

0:00:22.379,0:00:26.030
So what do scientists mean when they talk[br]about variants

0:00:26.030,0:00:29.735
and what might this mean [br]for the future of the pandemic?

0:00:30.854,0:00:34.828
Viruses multiply by copying their genomes[br]over and over.

0:00:34.828,0:00:38.953
But like an old photocopier, [br]these copies aren’t always perfect.

0:00:38.953,0:00:42.996
Each of these imperfect copies [br]is a variant.

0:00:43.120,0:00:47.376
Normally the imperfections or mutations [br]don’t change how the virus behaves

0:00:47.376,0:00:51.780
and they can often make it less successful[br]than the original strain.

0:00:51.780,0:00:56.431
But very rarely mutations can [br]change the virus in some important ways.

0:00:56.431,0:01:03.199
It could become more infectious,[br]or more able to avoid the immune system.

0:01:03.199,0:01:06.000
The more a virus is allowed [br]to replicate unchecked,

0:01:06.000,0:01:10.680
the more chance it has to accumulate [br]these rare beneficial mutations.

0:01:10.680,0:01:15.731
That can occur when viruses are allowed[br]to spread quickly through a population,

0:01:15.731,0:01:18.554
or if they encounter a host [br]that’s less able to fight them,

0:01:18.554,0:01:22.287
such as people with compromised[br]immune systems from medical treatment

0:01:22.287,0:01:24.417
or those who are HIV+.

0:01:24.417,0:01:28.657
If a particular set of mutations makes [br]a variant more successful,

0:01:28.657,0:01:31.096
it might become more prominent than others

0:01:31.096,0:01:33.757
and that’s when it gets noticed.

0:01:33.757,0:01:37.803
Epidemiologists may even decide[br]to label it a ‘variant of concern’,

0:01:37.803,0:01:42.330
like the examples identified in Brazil, [br]South Africa and the UK.

0:01:42.330,0:01:45.862
For months, scientists [br]have been striving to work out

0:01:45.862,0:01:49.960
what’s changed in these variants,[br]and what those changes mean.

0:01:49.960,0:01:53.283
Because a variant spreading [br]doesn’t necessarily mean

0:01:53.283,0:01:56.180
that it has an advantageous mutation.

0:01:56.180,0:01:59.710
For example a small number of people [br]could, by chance,

0:01:59.710,0:02:01.870
move a variant [br]from one region to another,

0:02:01.870,0:02:06.310
like tourists travelling back[br]from popular vacation spots.

0:02:06.310,0:02:09.592
This could cause that variant to start[br]spreading in a new location

0:02:09.592,0:02:13.794
even though there may be no significant[br]change to the biology of the virus.

0:02:13.794,0:02:17.200
This is called[br]the Founder Effect.

0:02:17.200,0:02:19.504
Understanding why a variant has emerged

0:02:19.504,0:02:21.828
requires a combination of studies.

0:02:21.828,0:02:25.259
Epidemiology can help detect [br]and trace new variants

0:02:25.259,0:02:28.444
and flag new or worrying [br]patterns of infection.

0:02:28.444,0:02:31.606
Meanwhile lab studies [br]can start to pinpoint

0:02:31.606,0:02:35.506
how the mutations are changing [br]the properties of the virus.

0:02:35.506,0:02:39.063
And studies like these [br]are starting to identify mutations

0:02:39.063,0:02:42.043
that have given the virus an upper hand.

0:02:42.043,0:02:46.940
Some variants are faster spreading,[br]and there are hints that certain mutations

0:02:46.940,0:02:52.510
could start to weaken or even evade [br]natural and vaccine derived immunity.

0:02:52.510,0:02:58.220
For example, the D614G mutation, known to[br]virologists as Doug, spread widely

0:02:58.220,0:03:02.290
in the early days of the pandemic [br]and can be seen in almost all variants.

0:03:02.290,0:03:04.662
It affects the spike protein

0:03:04.662,0:03:07.820
that coronavirus particles [br]use to penetrate cells.

0:03:07.820,0:03:11.246
A mutation in the genome changes [br]one amino acid for another,

0:03:11.246,0:03:17.409
and makes the new variant [br]more infectious than the original virus.

0:03:17.409,0:03:22.374
N501Y also known as Nelly, [br]is another spike protein mutation

0:03:22.374,0:03:25.658
which appears to be associated [br]with increased transmissibility.

0:03:25.658,0:03:30.508
This mutation has been detected[br]in the B.1.1.7, B.1.351

0:03:30.508,0:03:34.779
and P.1 strains - all variants of concern.

0:03:34.779,0:03:42.610
The worry of so-called ‘immune escape’ [br]has also been hinted at

0:03:42.610,0:03:43.610
with another spike protein mutation, E484K or Eek.

0:03:43.610,0:03:51.270
Eek has been spotted in B.1.351 and P.1, the[br]variants detected in South Africa and Brazil.

0:03:51.270,0:03:57.960
Lab studies in early in 2021 showed that the[br]variant could evade some virus-blocking antibodies,

0:03:57.960,0:04:04.590
while trials in South Africa suggested that[br]the variant reduced the efficacy of several vaccines.

0:04:04.590,0:04:09.820
Despite these worries, the coronavirus is[br]actually mutating very slowly compared to

0:04:09.820,0:04:16.699
something like influenza and it seems like[br]the vaccines developed so far will remain at least partly effective.

0:04:16.699,0:04:21.774
But scientists are still taking the threat[br]posed by variants seriously.

0:04:21.774,0:04:25.639
And there are several things that [br]can be done to help tackle it.

0:04:25.639,0:04:30.000
Firstly, to do anything researchers need data

0:04:30.000,0:04:37.169
- it’s very important to monitor and trace the emergence of [br]variants and that isn’t always simple to do.

0:04:37.169,0:04:41.668
Organisations like the COVID-19 Genomics UK[br]consortium, or COG-UK,

0:04:41.668,0:04:47.527
have stepped up their efforts to combine [br]fast sequencing with efficient data sharing.

0:04:47.527,0:04:53.330
COG-UK has already sequenced over 400,000 SARS-CoV-2 genomes.

0:04:53.330,0:04:58.910
Next, researchers need to look forward to[br]how these mutated viruses could affect global

0:04:58.910,0:05:06.617
vaccination efforts. Existing vaccines can be redesigned and[br]combinations of vaccines are also being tested

0:05:06.617,0:05:14.290
but it could be difficult to perform reliable [br]clinical trials amid the ongoing vaccination programmes.

0:05:14.290,0:05:18.497
Right now though, work needs to continue at[br]a national level.

0:05:18.497,0:05:23.654
Public health policies such as track and trace, social distancing and vaccine roll-outs

0:05:23.654,0:05:30.849
are powerful tools to interrupt transmission and keep tabs on new variants.

0:05:30.849,0:05:34.441
After all, every time the virus is prevented[br]from spreading,

0:05:34.441,0:05:36.986
it's also prevented from mutating,

0:05:36.986,0:05:41.525
nipping new variants in the bud[br]before they even have a chance to develop.