this episode was filmed on august 10th
2021 for more updates on the covet 19
pandemic check out our playlist linked
in the description
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ready for some more covid news
yeah i know me either but we wanted to
talk about something that's been in the
news and that you may even have
questions about the delta variant so in
this episode we're going to talk about
what it is why it's here and what you
need to know the delta variant is a
strain of the sars cov2 virus which is
the virus that causes covet 19. it's one
of several variants that's acting unique
enough to qualify as a distinct strain
those get greek letters for names right
now like beta and gamma plus the first
dominant strain alpha since it was
identified in late 2020 it's quickly
becoming the dominant strain in many
parts of the world that includes
countries that had successfully managed
earlier strains and relaxed public
health measures like the us and france
and what makes this variant worrisome is
that it looks like it's more easily
transmissible than previously dominant
strains the world health organization
says that the delta variant is the most
transmissible of the variants identified
so far we don't yet know why it's able
to spread so much more readily though
one study has proposed that it's because
infected people have higher viral loads
that is more copies of the virus in
their bodies if that's true that would
mean that the delta variant reproduces
faster and is more infectious at early
stages than other dominant variants this
variant may also affect our bodies
differently than previous dominant
versions of the virus the study i
mentioned also suggested high viral
loads may be related to a shorter
incubation time meaning infected people
show symptoms faster however that paper
has not yet been published or passed
through peer review so we'll need
further confirmation other data
indicates that the delta variants
symptoms might be slightly different
with headaches fever sore throat and
runny nose being common while cough and
loss of sense of smell aren't it also
comes with some new symptoms including
hearing loss but are those infections
more severe well we're not sure yet some
experts say that may be likely and there
are some reports that the delta variant
may be more likely to lead to severe
illness compared to other strains and a
report from scotland suggests
hospitalization for unvaccinated
individuals is twice as likely if the
patient is infected with the delta
instead of the alpha variant it might be
that the delta variant is more dangerous
or that it's spreading faster through
more vulnerable populations and easing
up of public health measures has
certainly played a role as well the
situation in india seems to have been a
perfect storm their vaccination campaign
was just starting to get going officials
had relaxed restrictions on large public
gatherings and that plus the heightened
transmissibility may have let the delta
variant spread through the population
rapidly but it's not a simple matter of
india relaxing social distancing and
other public health measures because
here's where we run into another wrinkle
in australia most of their public health
measures like contact racing and social
distancing have been seen as a model
worldwide and the delta variant has
punched right through them relatively
speaking anyway for most of 2021
australia has managed under 100 new
cases a week but since july that number
has skyrocketed to around 2000 a week
that's still low compared to some
countries but it's pretty troubling what
australia hasn't had so far is a high
vaccination rate but even vaccinated
individuals may need to be wary there's
been a lot of attention paid to
so-called breakthrough infections which
is where someone who has been fully
vaccinated still gets sick there have
been a few well-documented outbreaks
that included a substantial number of
vaccinated people now it's worth noting
that some breakthrough cases are
expected no vaccine is ever perfectly
effective at preventing infection it's
also worth a reminder that most of the
vaccines in use right now were first
tested around their ability to prevent
severe disease not necessarily stop
transmission later on we did begin to
see evidence suggesting that they could
help halt the disease but that wasn't
the actual primary goal and while we
don't have much in the way of separate
data for the delta variant overall it
does appear that the vaccines we have
are still working by that measure
they're helping to prevent severe
disease and death data from the world
health organization suggests that a
number of vaccines including moderna
astrazeneca and cynovac have so far been
over 80 effective against severe disease
hospitalization and death so the
question becomes whether the delta
variant is more likely than others to
infect vaccinated people and whether
those people would go on to spread it
and i said we didn't have much data
concerning vaccines in the delta variant
but we have some a paper published in
july in the new england journal of
medicine suggested that two doses of
both astrazeneca and biontech pfizer's
vaccines are effective against the delta
variant they lost only a few percentage
points of efficacy compared to an older
strain now both of those vaccines are
administered in two doses and the paper
did find that only a single dose of
either was less effective against the
delta variant dropping from about 50 to
only about 30 percent that seems to be
the case for other variants as well
altogether it is possible for someone
who is fully vaccinated to be infected
with any variant according to the cdc
and some preprint data people with
breakthrough infections of the delta
variant may have a viral load just as
high as someone who isn't vaccinated and
remember the delta variant viral load
might be a lot this has raised concerns
about how much vaccinated people might
still spread the infection though it's
worth noting that high viral load isn't
necessarily an indication of heightened
infectiousness it could be that those
viral particles are present in the body
but have been deactivated by the immune
system so they're not actually a problem
and as more people get vaccinated the
proportion of breakthrough cases to
normal cases will rise because the
proportion of vaccinated people to
unvaccinated people will rise and you
can't have a breakthrough case unless
you're vaccinated that's what it is so
what can we do well we don't have a lot
of concrete answers regarding the delta
variant but remember that vaccines still
seem to work by work here i mean that
they help limit severe illness
hospitalization and death even if people
do get sick some other vaccine
manufacturers are looking into booster
shots but many public health experts say
they would rather focus on getting to
people who haven't yet had an
opportunity to get even a first dose and
this isn't just a question of logistics
but equity as most of the available
vaccines have gone to rich countries so
far leaving many vulnerable populations
waiting and we still do have all the
stuff we had at the start of the
pandemic i'm talking about your
quarantining if you feel sick you're
washing your hands all that good stuff
these will continue to be an important
part of limiting spread as much as
possible we can see from australia's
example that social safety interventions
like distancing aren't bulletproof but
vaccines in the absence of those same
measures aren't enough either because
breakthrough infections can happen and a
lot of people remain unvaccinated it's
going to take a comprehensive strategy
to stay ahead of this thing meanwhile
experts are keeping an eye on this and
other variants like lambda which also
appears to be more infectious and
possibly resistant to vaccines so
unfortunately even though we all really
really would love to believe otherwise
kovid isn't over yet thanks for watching
this episode of scishow we hope it
brought a little clarity to the
confusing ongoing situation that we find
ourselves living in and of course we
couldn't make videos like this one
without the help of our patrons if you'd
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scishow
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