Welcome to another MedCram COVID-19 update, and we're gonna be talking about the AstraZeneca
vaccine in this update.
But first, let's take a look at the numbers real quick.
Daily new cases in the United States are at an all time high.
But it may be peaking.
We don't know, need to get some more data here.
But if you look at the data you can see that there has been somewhat of a slowdown in the
number of cases.
Of course with deaths, they lag behind, maybe a couple to three weeks, and the daily new
deaths are increasing as well at this point.
Again, we're gonna have to wait for further data.
So now we're gonna talk about the AstraZeneca-Oxford vaccine, and we're gonna compare to the ones
that have gone before it, like the Pfizer-BioNTech vaccine, and the Moderna vaccine.
Now, as you will recall, the Pfizer-BioNTech vaccine and the Moderna vaccine are basically
new vaccines in the sense that they are injecting messenger RNA into your cells to tell the
cells to produce the protein that is the same as a portion of the spike protein that is
on the virus, and that is what generates the immune response.
So in other words, we're giving instructions to the cell to make the form protein, which
causes the immune response.
And that is actually very similar to the AstraZeneca-Oxford vaccine, except, instead of using messenger
RNA, they're using DNA to do that.
So once again, in terms of a picture, imagine we have the cell and we've got the nucleus.
And what we were doing before, was we were taking messenger RNA and that messenger RNA
was being translated by ribosomes and converted into the protein.
And what we did with the Pfizer-BioNTech vaccine and the Moderna vaccine, is we were getting
the messenger RNA into the cytoplasm of the cell.
The cytoplasm is the outside portion, as opposed to the nucleus.
How do we get that messenger RNA in the Pfizer-BioNTech vaccine and the Moderna vaccine in?
Well we used a lipid bilayer, or a micelle as we called it, to get those fragments, or
the messenger RNA, into the cytoplasm.
And then from there, it's fairly straightforward.
The cell uses its own cell machinery, which is the ribosomes, to cause translation to
occur and you make the protein in question.
How this is different is AstraZeneca uses a different technique.
And it uses a virus called an adenovirus, but not a human one, but a chimpanzee.
Now why would it do that?
Chimpanzee adenoviruses have not really been exposed to the human population, so it's very
unlikely that humans would create an immune response against the adenovirus specifically
itself.
We don't want that to happen.
Because if that happens, then the vaccine is not going to be effective at getting its
instructions into the cell.
And of course, AstraZeneca knows that if this vaccine is successful and is used on a number
of people -- millions, billions of people worldwide -- then it's probably going to have
to abandon the chimpanzee adenovirus platform for delivering instructions.
Now, the adenovirus here does not use RNA, like we've been talking about.
It uses DNA, and DNA is a double-stranded form of instructions.
Now, there's a portion there in the middle of that, that is used for replication of the
virus.
Well, the genetic engineers simply delete that portion, so the virus can no longer replicate
and cause an infection in the human body, and instead they replace that portion of the
DNA with genetic code (the instructions) that the geneticists have engineered.
And so what happens when you deliver this adenovirus in the vaccine, it goes into the
cell and it releases the DNA into the cytoplasm, and then that gets taken up and goes into
the nucleus.
That DNA -- according to scientists at AstraZeneca -- does not get incorporated into the host's
genome.
It does not go into your DNA in the cell, but rather it is transcribed into RNA, and
that RNA then exits the nucleus as a messenger RNA and then exactly the same thing happens
as what we saw with the Pfizer-BioNTech vaccine and the Moderna vaccine, which is that the
messenger RNA, which is now a product of the transcription of the DNA, gets converted into
the spike protein through translation by the ribosomes and then this goes on once again
to cause the immunogenic response.
Now there's a couple of points that you should understand about the trial, the AstraZeneca
and Oxford trial, that's been looking at this vaccine.
And let me just stress to you that the results that we have gotten here in the last few days
are via press releases and not peer-reviewed articles that have been published and reviewed.
So the first differences we talked about is that it is a DNA virus platform.
And there's been many areas that they've been doing research and predominantly, let's take
a look at two of those areas.
The first one was in Brazil, and the second area that they did the trials was in the UK.
Be also aware, though, that they are doing trials in the United States as well.
And from the numbers -- and I'm rounding these off -- there's been about 9,000 people that
have been enrolled in Brazil, and about 3,000 that were enrolled in the UK.
Now, just like the other two vaccines that we were talking about, this is also a two-step
process.
So, there's two injections, or two vaccinations, and they're about a month apart.
Now by some error that occurred in the UK trial, they gave half a dose first, followed
by a full dose.
Now, in the Brazil trial, they gave a full dose, like they were supposed to, followed
by a full dose, and this happened approximately 28 days apart.
Now, if you've listened to us when we talked about the other two vaccines, you'll know
that in those other two vaccines they did the trial a little differently in terms of
the fact that they waited for subjects to become symptomatic with COVID-19 symptoms
before looking at the end point there, or a midway point, to see whether or not the
vaccine was effective.
Here in the AstraZeneca case, they were not doing it that way.
No, in fact they were doing swabbing and they were checking for infections.
This is a huge deal, because whereas with the Pfizer-BioNTech vaccine candidate and
also the Moderna vaccine, all we can really say about those two -- even now with the results
that we have -- is that it is definitely effective if what they're saying is true at preventing
the symptoms of COVID-19, at preventing the disease, at preventing the things that cause
people to go to the hospital.
What we don't know right now about those two vaccines is whether or not the vaccine prevents
infections.
And that's important because infections leads to transmission and transmission leads to
spread of the virus.
Now here with the AstraZeneca-Oxford study, they actually checked for infections by doing
nasal swabs, and so what we can say here is that whether or not there has been a stoppage
or a ceasing of transmission and therefore infections.
Now what was really interesting and kind of a headscratcher is in the Brazilian portion
of this study where they gave the full dose on the first injection and the full dose on
the second injection, the efficacy was only about 62 percent.
Now I say "only" because we're comparing it to what we know now about the other two vaccines,
but 62 percent is not a bad result.
And it certainly meets the benchmark, or the threshold, for getting emergency-use authorization
from the FDA both here in the United States and also in Europe.
However, the part that's kind of a headscratcher is that when they, by some serendipitous error,
they injected the subjects in the UK with half a dose on the first shot and then a full
dose on the second shot, this one was actually 90 percent effective, and that's not just
for preventing COVID-19, as I said.
That may also, according to the preliminary results, prevent infections from what they're
telling us.
And so the US trial was paused because there were some events in two subjects in the United
Kingdom, and one subject in Brazil, that was deemed later not to be related to the vaccine,
but it took them time to investigate.
They have restarted the USA portion of the trial, but now they want to see if they can,
in midstream, modify that to introduce some half-dosing as well, combined with perhaps
full-dosing to see whether or not they're going to get a similar result, either 62 or
90 percent or something in between.
Now the other thing that was very interesting about this is that obviously some people are
getting placebos, but in not every situation are those placebos just saline or salt water.
In fact, in the first injection, what they have been doing is getting a meningitis vaccine
dose, because they wanted to reproduce the symptoms that people got when they got an
injection.
Because when you get an injection with saline, it doesn't cause irritation at the site as
much, it doesn't cause pain at the site as much, but a regular vaccine that would have
nothing to do with coronavirus, such as a meningitis vaccine, might do that.
And so , AstraZeneca-Oxford trial is a little different than the other two in that they
were giving other vaccines as placebo.
And the reason that they're doing this is to get a more realistic placebo effect so
that the subjects can't tell whether or not they've gotten the vaccine, in this case,
or whether they're in the placebo arm.
So what are the other possible advantages?
Well, with the Moderna vaccine, as we talked about, it had to be stored, if you wanted
to store it for 30 days, at negative 20 degrees centigrade or negative 4 Fahrenheit, and as
you recall from the Pfizer vaccine, it was even more extreme.
It was at negative 70 degrees Centrigrade or negative 94 degrees Fahrenheit to store
it for six months.
Here, just a regular refrigerator is all that is necessary.
In fact, it only needs to be stored at 2 to 8 degrees Centrigrade or 36 to 46 degrees
Fahrenheit.
So those are some advantages there.
And of course because of that you don't need to build an infrastructure system, you just
need regular refrigeration to store this vaccine.
The other thing that's very interesting as well, is that AstraZeneca has promised not
to make any profit during the pandemic on this vaccine.
And so while the cost of giving the other two vaccines is around the $20 range, the
AstraZeneca-Oxford vaccine is going to be sold for anywhere between $3-5.
And not only that, the AstraZeneca-Oxford vaccine is potentially going to hit about
3 billion doses.
And what's interesting is that because they only needed a half dose for the 90 percent
efficacy, they would actually be able to save some of that material and that could immediately
go as high as 4.5 billion doses worldwide.
The other thing thats interesting politically as well is that because the United Kingdom
is leaving the EU, they would be able to get this fast-tracked within their own country
without depending on EU approval.
However they are applying for EU approval as well.
Other things that came out in the press release is that there were no serious side effects.
The other thing that said too was that there were not severe COVID cases in those patients
that got the vaccine.
So let's review: how is the AstraZeneca-Oxford vaccine similar to the Pfizer-BioNTech and
the Moderna vaccine.
Well, it's similar in that two vaccinations are necessary, approximately one month apart.
It's also similar in that it delivers the instructions to the cell, for the cell itself
to make the protein antigen that stimulates the body to make the immune response.
But this candidate is different in the fact that it's a DNA virus.
It's also different in that it doesn't really require subzero temperatures to preserve it.
It's also different in terms of the fact that it's going to be a lot more affordable, especially
for countries that don't have the infrastructure to keep these vaccines at very low temperatures.
And it's also different that there is this headscratcher type of situation here, where
we don't really understand why this small UK group had such high efficacy especially
with only half the dose on the first dose.
So right now we're kind of feeling around in the dark.
What we really need to have and what we are going to have very shortly is the actual data
released that will be peer-reviewed and published.
And if you want to read more about this, I'm going to put in the description below the
links where we got this information from, so you can do more research and find out for
yourself.
If you want to hear more medical topics explained clearly, please visit us a MedCram.com.
Thanks for joining us.