- [Narrator] New coronavirus variants
have been detected in over 40 countries,
including the UK, South Africa, Nigeria and Brazil
where they first emerged.
- Now health officials say a new threat
is identified in South Africa.
- British officials imposed a new lockdown across England.
- Recent reports of a highly contagious coronavirus variant
in the United States.
- [Narrator] In the US, multiple states
have reported new variants
or versions of the virus with mutations
that could change how it spreads.
New research suggests
that some of these variants are highly transmissible
and at least one may reduce how well vaccines work.
With countries around the world
already facing escalating infections
and overwhelmed hospitals,
these mutations could make ending
the pandemic more difficult.
We'll explain.
Like other viruses, the coronavirus spreads
by infecting cells and then reproducing within them,
creating copies of itself that spread throughout the body.
As new versions are made, the virus' genetic code,
which holds the instructions
for building new virus particles is copied over
and over again.
But the code isn't always reproduced correctly.
Small genetic mistakes or mutations
can create new viral variants.
If the new version of the virus has mutations
that allow it to spread faster
than the current most common variant,
it could lead to a surge in new cases.
This is already happening in places
like the UK and South Africa
where some of the newest ones were first found.
Current data suggests that the UK variant
could be 50% to 70% more transmissible
but the research is still early.
To determine how transmissible
and dangerous a virus mutation might be,
scientists run a series of experiments in the lab.
The first step is genetic sequencing.
- Genetic sequencing gets to the blueprint
of what the viruses are.
We can use samples and data
from actual humans to figure out
what the genetics of the viruses are.
- [Narrator] To do this, scientists take a sample
of the mutated virus and sequence its genes.
Then computation programs
help scientists identify mutations.
- Once we know what they are
and now we can see that oh well,
this is an important population,
we can start manipulating the virus.
We can either start working with clinical islets
of that virus or we can actually make the strains.
So putting those individual mutations
into the backbone of viruses that we already have.
- [Narrator] After sequencing the virus,
scientists test the variant in a lab.
- What we do is we compare how well the virus replicates
in different types of cells.
And so there are two ways.
We will just do infections and kind of measure the level
of the virus over time in these cell types.
And the other thing that we'll do is a competition,
where we'll take 50% of the wild type,
the original strain and 50% of the mutant strain
and then compare how well they grow.
If there's an advantage, we'll see that
that advantage 24 hours or after 48 hours,
one of the two might out compete.
- [Narrator] During lab experiments,
researchers can also test whether human antibodies created
by infection or vaccines
are effective at fighting the new form of the virus.
After culture testing,
scientists typically move on to animal models
and then sometimes to humans.
Right now, the research is still early
but scientists are beginning to get a clearer picture
of what these variants look like.
From sequencing, they know the UK variant
has 17 key mutations.
- These variants that we're seeing,
these changes give a small advantage
in terms of the ability of the virus
to replicate or transmit.
- [Narrator] This has a lot to do with the spike protein,
which is critical to how the virus spreads.
A portion of the spike bonds to a receptor
on human cells like a key fitting into a lock.
This enables it to enter and infect.
Scientists found that the UK variant's spike proteins
have eight amino acid changes.
Previous research appears to show
that some of these changes may be increasing
the protein's ability
to cling onto and enter human cells.
This could be making it more transmissible,
which means a higher vaccination rate may be needed
to reach herd immunity.
Another big question is the virulence
or how harmful these new versions of the virus could be.
Scientists say that most likely the new variants
don't cause a more severe form of COVID-19.
Another question is whether the new versions
will show up on tests.
Early data appears to show that most COVID
and antibody testing will continue to work.
- We should still be able to tell if you have COVID.
What's less clear is if we can tell
if you have a specific variant or not.
- [Narrator] The most pressing issue
is whether vaccines will still be effective.
For the UK variant, it appears that they will.
However, for the variant originating in South Africa,
preliminary data is worrying some scientists.
Researchers say that any of the more transmissible variants
could eventually become dominant.
- We've seen variants take over
in terms of the D614G mutation
and it wouldn't surprise me if the South African
or the UK variant do a similar thing
where it becomes a dominant variant around the world
just because of a small fitness advantage
or small changes that make the virus more fit.
- [Narrator] To try to stem the spread,
certain countries like the UK
have already imposed strict lockdown measures.
- The number of patients in hospitals in England
is now 40% higher than the first peak in April.
It is inescapable that the facts are changing
and we must change our response.
And so we have no choice
but to return to a national lockdown.
- [Narrator] While the new variants are concerning,
experts say that current prevention measures
should continue to work.
- This isn't something that's completing overcoming masks
or distancing and so if these measures
were put in place in more stricter,
more effective ways,
it'll be just as effective, if not more effective.
And the outcome may be that being a little bit more serious
about this will get transmission as a whole
to be reduced and I think that's an ideal.
- [Narrator] Scientists say the coronavirus pandemic
could be on the cusp of a major shift
but more research is needed
to know how severe the impact
of the new variants will be.
(dramatic music)