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This episode was filmed on January 19th, 2022.
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[♪ INTRO]
Throughout the COVID-19 pandemic we’ve
seen new variants of concern of SARS-CoV-2,
the virus that causes COVID-19.
The World Health Organization gives
names to new versions of the virus
that it determines might have more of an
impact on people, say by spreading more easily,
causing more severe disease, or being better
at getting around our body’s defenses.
The latest variant making headlines is Omicron.
It was first identified in late November of 2021.
But as is always the case with this pandemic,
we’re still trying to learn about its effects,
and what this new variant means for
the overall course of the pandemic.
Here’s what we know right now.
Omicron is spreading quickly, and many experts
predict it will overtake the Delta variant
as the dominant variant of SARS-CoV-2 worldwide.
You or your loved ones might have already
been affected by it, given its rapid spread.
Part of the reason for the rapid spread is
that this version of the virus appears to be
more infectious, meaning more likely to spread
from person to person, than previous ones.
For example, data from the UK and Denmark
suggest that Omicron is more likely than Delta
to spread within a household, even in
cases where all members of that household
had been vaccinated and received booster shots.
The Danish study is a preprint, meaning
it has not been published or peer reviewed
but has been uploaded to a pre-publication server.
There’s no guarantee these preprints are correct,
as they haven’t been through the
usual process of scientific scrutiny,
but they are a way to share potentially
important information quickly.
We’ll be talking about a few
other such studies today.
With that out of the way, the reason for
the heightened infectiousness might be
because Omicron is more adept at dodging the
antibody defenses that vaccines give us.
Take one lab study, published in the journal
Cell, which looked at people who had been fully,
recently vaccinated with either the
Moderna or Pfizer/BioNTech mRNA vaccines,
or the Janssen viral vector vaccine.
Half the people who had been
fully vaccinated, but not boosted,
couldn’t mount an immune defense against Omicron.
On top of that, preprint data out of
South Africa suggests previous infection
with a different variant of the virus also
provides little immunity against Omicron.
It also showed that people can
become infected more than once.
However, other preprint data
suggest that the Janssen vaccine
does provide protection against hospitalization,
so this one might need more time to untangle.
Why? Well, most of these papers focused on
the neutralizing antibodies our immune system
produces in response to a vaccine or the virus,
but that’s not all our immune system does.
So the vaccines may be helping our immune
systems protect us from Omicron in other ways.
Like the variants that came before
it, Omicron has a number of mutations
compared to earlier versions, including
many that affect its spike protein.
These may make it better at both infecting cells,
and avoiding antibodies that target the spike.
It also seems to affect different parts
of the body compared to previous variants.
Preprints from Hong Kong and the UK have
found that it’s up to 70 times better
at replicating in the nose or upper airway than
Delta, which hangs out more in the lungs.
More virus particles in the nose and throat
could mean it’s easier to sneeze or cough it out
and help the virus spread.
Hanging out in the upper airway could also be why
this variant seems to cause less severe disease.
This also may be why the reported symptoms
of Omicron are slightly different:
more runny noses and sore
throats, and more ear aches,
because everything is congested up here.
Now, there seem to be fewer hospitalizations
around the world for Omicron than Delta,
especially for vaccinated individuals.
And when those hospitalizations do happen,
people tend to stay in the hospital for around
70% less time regardless of vaccination status,
according to one preprint
study out of California.
Plus, a British report from December 2021
found that the risk of being hospitalized
because of an Omicron infection was
around a third of the risk for Delta.
This was a pretty small study, though, so take
the numbers with a statistical grain of salt.
But – and this is a big but – the number of
hospitalizations is going up. And quickly.
There’s still going to be a subset
of people who become seriously ill,
even if the variant is milder.
So if case numbers are high, that still represents
a large overall number of people who will need
hospital care, and who may develop the group
of long-term symptoms known as long COVID.
The question on a lot of people’s
minds now is what Omicron means
for the future of the pandemic.
One of the big questions is
how the virus will evolve.
As in, whether we’ll keep seeing not just new
variants, but new variants that are dangerous.
Researchers have warned that as the virus
continues to spread around the world unchecked,
that creates opportunities for new mutations
that might turn into a variant of concern.
So slowing transmission is as
important as it’s ever been.
Fortunately, we’re not back to square 1.
We know far more about this
virus than we did in early 2020.
We know that non-pharmaceutical public
health interventions like social distancing,
limiting the number of people in enclosed spaces,
and testing and tracing policies will
continue to play a role in our response.
Some people have predicted that
COVID-19 will become an endemic disease.
That is, one where the disease is
always present in the community
and causing infections on some level.
However, many other experts point out that that’s
not a good outcome, whether or not it’s likely.
Seasonal flu is an example of an endemic disease
that still comes with a
significant death toll every year.
Endemism is also slightly different from herd
immunity, which you may have heard discussed.
That’s where most people have immunity
and the disease can only spread
within particular sub-populations
who aren’t immune.
And that’s something that experts
were never really banking on,
despite public figures talking it up.
Because this virus is just too good at
shifting into new forms for the defenses
we get from vaccines, or prior
infection, to completely wall it off.
It’s different from, say, measles,
where vaccination is effective
at preventing disease in most people.
But vaccination will still be a valuable tool.
Expanding vaccination to as many people
as possible worldwide will give the virus
fewer opportunities to mutate into new
variants, as overall infections decline.
Plus, some scientists are using data
from all of the known previous variants
to try to build predictive models
of what might be around the corner.
A recent study in Science Translational
Medicine looked at what mutations have helped
a particular virus variant spread in the past.
The researchers analyzed what features
of that mutation helped it spread,
and developed a computer model that they used to
retroactively predict which mutations
have spread up to four months in advance.
Now they hope to use the model as a starting point
to help us prepare or screen for new variants.
So when it comes to Omicron,
we’re not reliving March 2020.
But there are also still lots of unknowns,
and this is still a dangerous virus.
So stay safe, everybody.
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Even better, if you check them
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[♪ OUTRO]