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Go to Brilliant.org/SciShow to check out their
Knowledge and Uncertainty course.
[♪ INTRO]
This video was filmed on September 1st, 2020.
For the most up to date information we have
on the COVID-19 pandemic,
please refer to the playlist linked in the
description.
On August 11th, Vladimir Putin announced Russian
health agencies had approved
the world’s first vaccine for widespread
use against COVID-19: Sputnik V.
Yes, that’s really what they decided to
call it.
And it’s potentially really good news!
But, many experts are skeptical as to whether
the vaccine actually works,
because it’s been tested in a really weird
way.
Vaccines are technically drugs, and get approved
by regulatory drug agencies.
They’re supposed to publicly prove themselves
in a very specific set of scientific tests.
This is, in large part, why vaccines as a
whole are so safe and effective.
But this is not what happened with this Russian
vaccine.
Its developers haven’t published any of
the results from human tests.
And they claimed success even before starting
the kind of testing you need to see if a vaccine
actually works.
Alright, so, to back up: drug trials in humans,
also known as clinical trials,
are typically organized into four to five
stages, or phases.
These can sometimes be combined, but they’re
usually discrete,
because each builds on the previous ones.
In the US, they are creatively named Phases
0, I, II, III, and IV.
But Phase IV actually happens after the drug
hits the market,
so we’re going to focus on Phases 0 through
III here.
Phases 0 and I are generally short, small
studies intended to establish that
the drug does the very basics of what it’s
supposed to do,
and doesn’t cause tons of harm in the process.
Since these trials are usually the first time
a drug has been given to people,
researchers are really watching out for negative
side effects, or, in trial lingo: adverse events.
They also generally try to figure out what
dose would be best.
For instance, a Chinese company called CanSino
began a Phase I trial for their COVID-19 vaccine
on March 16th.
They gave 108 participants a low, medium,
or high dose of the vaccine.
And while quite a few of those people had
mild to moderate side effects
like fatigue and headaches, the vaccine appeared
safe enough to use in people.
So, it moved to Phase II.
Here, scientists continue to look for adverse
events and evaluate dosing.
And the question of whether the drug actually
does anything becomes more prominent.
Participant numbers also typically go up.
Like, CanSino’s Phase II tested two different
doses against a placebo in about 500 people.
And, as hoped, vaccinated participants started
producing antibodies
that can neutralize the virus, and had other
promising immune responses as well.
Now, at this point, you might be wondering
how Sputnik V fared in its Phase I and II
trials. And so is everyone.
Although two combined Phase I and II trials
for it
are listed online as “complete”, their
results haven’t been published.
So, everything we know comes from the Russian
government and the researchers involved.
There’s no public data about how the vaccine
works, or how well those trials went.
But more to the point: even if they did go
well,
positive Phase II results don't guarantee
the vaccine works in the real world.
While things like antibody levels are associated
with protection in animals,
immune reactions are complicated.
And Phase II trials don’t actually test
whether a vaccine prevents people from getting sick.
That doesn’t happen until Phase III.
These trials are typically hundreds, thousands,
or even tens of thousands of participants
larger.
That’s in part because researchers want
to see
if or how many people catch the disease after
getting the vaccine.
So, they need lots of people, to make sure
that a good number of them
are exposed to the virus in their daily lives.
And that can take a long time,
which is why Phase III trials usually take
a year or years, start to finish.
Another reason for the big numbers at this
phase is to spot rare and serious adverse events.
Even something that happens once in every
ten thousand vaccinations
can be a big deal, since we may want to vaccinate
hundreds of millions of people.
And these also can take some time to manifest.
So Phase III trials are really important,
both as measures of how well a vaccine works
and how safe it really is, and their large
numbers and longer time tables are key to all of that.
Now… when Putin made the announcement,
it wasn’t clear if Russia was planning to
start one of these trials.
Since then, other sources have said that the
vaccine’s approval is actually dependent on
positive Phase III results, and that those
trials have started,
or will start soon?… in several countries;
the details are still fuzzy.
Even if that’s the case, though, government
officials have also said that
they want to start administering this vaccine
in October,
which wouldn’t give those trials time to
show anything.
That’s why doctors and public health experts
are so unnerved by how this is all playing out.
Now, Russia isn’t the only one taking risks
or skipping steps
in the hopes of delivering a vaccine as soon
as possible.
Like, here in the US, a company called Moderna
launched into Phase I and II trials
for their COVID-19 vaccine before completing
pre-clinical trials in animals.
Then, they went into Phase III before finishing
Phase II
or publishing the full results from Phase I.
Also, the pharmaceutical company Pfizer announced
that
they may apply for FDA approval for their
vaccine candidate in October,
even though it'll still be in Phase II and
III trials.
And while it would be unprecedented for the
FDA to grant them that approval,
this week, the FDA commissioner said the agency
might consider
an emergency use authorization, if a company
submitted compelling paperwork before the
end of clinical trials.
Which in another way, isn’t that unusual;
we have emergency authorizations for other
COVID-19 therapeutics in America.
And China has implemented their own version
of
emergency vaccine authorization for their
military and at-risk citizens,
even though their vaccines are still in clinical
trials.
But that’s not what Russia initially said
they were doing,
and it’s still not entirely clear what’s
going on.
They seem to be all in on this as yet unproven
vaccine.
And that’s a pretty risky bet, considering
that more than a third of drugs
that do well in Phases I and II fail in Phase III.
It’s possible, of course, that the gamble
will pay off.
Sputnik V could be a safe and effective vaccine.
But, if the vaccine doesn’t work, or worse,
proves truly harmful,
it could hurt a lot of people, undermine control
efforts,
and ruin everyone’s trust in whatever vaccine
or vaccines succeed it.
It would be amazing if this vaccine pans out.
But over the years, we’ve developed a very
specific and rigorous method
to make sure any drug or vaccine is as effective
and safe as possible.
And this one isn’t following it.
So, at this point, all we can do is wait and
see.
All this uncertainty surrounding, like, everything
to do with this pandemic is hard.
Uncertainty is hard in general.
But you can become better at dealing with
everything you don’t know,
with a little help from today’s sponsor,
Brilliant.
Their Knowledge and Uncertainty course dives
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So, check it out if you’re interested. And
thanks for watching SciShow!
[♪ OUTRO]

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