DESCRIPTION:
You might be wondering what we know about Sputnik V, the world¡¯s first vaccine
for widespread use against COVID-19. Well, so is everyone. Many experts are
skeptical as to whether the vaccine actually works, because it¡¯s been tested
in a really weird way.
TRANSCRIPT:
This episode of SciShow is supported by Brilliant. Go to Brilliant.org/SciShow
to check out their Knowledge and Uncertainty course. 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 500people. 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 deep into the math behind
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And thanks for watching SciShow!
QUESTIONS:
1. What comes to your mind when you hear the word vaccine?
2. What do you know about Sputnik V? Talk about it in detail.
3. Is the Russian vaccine for covid-19 really successful and available
for human use? Why or why not?