It looks like the association between AstraZeneca’s vaccine and a rare clotting/bleeding syndrome is real. Here’s what that means.

Here’s the Science review summary article with links to the primary studies.

ADDENDUM 4/13: as mentioned in the video, Johnson & Johnson’s vaccine has a similar adenovirus vector technology, and we are now seeing similar cases associated with that vaccine as well. US officials have recommended a pause in its use as they are investigate, read more here.


Transcript Below

Hey, everyone. What’s going on with AstraZeneca and blood clots? It’s back in the news, and it should be, because it looks like the association is actually real. In very rare instances, the AstraZeneca vaccine is associated with unusual blood clots with low platelets, a kind of syndrome that looks like something in medicine that we call heparin-induced thrombocytopenia, which is a reaction to a drug. What I wanna talk about today is, well, what does that mean for that vaccine?

What’s the science behind what we know so far? And how does it relate, potentially, to the Johnson & Johnson vaccine which uses a similar adenovirus DNA vector strategy? So let’s get into this right now. And you can share this with your friends. The language is gonna be clean. It’s not gonna be judgy or weird. It’s just gonna be science. All right, here we go. When they rolled out the AstraZeneca vaccine in Europe, about 34-odd million people got it.

They noticed about 222 cases of very unusual blood clots. Not your standard clots. Clots in the venous sinuses of the brain, in the veins of the gut. Really stuff that you don’t see every day. So the background rate of this stuff is low, which is why it’s kinda easy to catch. You can go, wait, that’s not normal. You don’t see that every day. And these syndromes were associated with low platelets, what we call a consumptive coagulopathy.

That’s a fancy way of saying, our platelets help us clot, there’s something going on where the platelets are being consumed, forming blood clots everywhere, and then we have low platelets, which means now we’re at risk for bleeding. So it’s this weird paradoxical syndrome where you can both clot, that can be deadly, and bleed, that can be deadly and cause real problems. There’s the syndrome called heparin-induced thrombocytopenia where we give a medicine called heparin, which is a blood thinner, and in rare cases, people form antibodies to a complex that forms between heparin and something called platelet factor 4, or PF4.

These antibodies that you form actually cause clotting. They activate a clotting cascade, use up all your clotting stuff and you get the syndrome that we just described. So the question then is, when they started looking at these new clots that were forming in patients who are, like, five or 10 days out from getting their dose of the AstraZeneca vaccine, they were like, “Wait, this looks a lot like heparin-induced thrombocytopenia.”

And there’s a group in Germany that published in “New England Journal of Medicine,” and I’m gonna be linking to the “Science” article that reviews what they did along with their primary data in “New England Journal,” and they say, “Hey, this looks a lot like that, so I wonder if there are antibodies against platelet factor 4 in these patients.” And lo and behold, when they looked at the patients, there were. So very similar mechanism here, antibodies against PF4, but they’d never gotten heparin. Why was this happening?

Something going on with that vaccine was associated with antibodies against PF4 and then this syndrome in extremely rare cases, right? And we’ll talk about how rare in a second because that’s important for context of risk. So they then said, “Okay, is this real? Is it higher than the background rate? Well, it looks like it probably is. Is there a mechanism for it? What could it be? What could be happening?” And, you know, when you read the case reports, you know, these are young people, often women, median age, 36. The spread was between 22 years old and 49.

The index case was a 49-year-old healthcare worker who had just, five days or so after the vaccine, had the stomach ache, wasn’t feeling well, some headache, fevers. Found to have a blood clot in the blood vessels of the gut. Was put on blood thinners, ended up bleeding. On autopsy, had more clot in the, one of those unusual clots in the brain. I mean, she died. So this was a big deal. And the platelets were low, and that started this search for, okay, what’s going on? Now, in the article in “New England Journal of Medicine,” they found these antibodies.

Now, further data said, “Well, okay, so what could be causing this?” And here are the theories, okay? First of all, could it be that they just were infected with COVID and didn’t know it? We know that COVID causes blood clots at a high rate, high rate, like 16% or something ridiculously high, people who get, you know, clinical COVID. So they then looked into that very carefully. Nope, none of these people had any evidence of being infected with coronavirus, so it wasn’t that. Well, then could natural coronavirus infection with spike protein be similar to vaccine?

Because the vaccine is, you know, causing you to make this spike protein, coronavirus has a spike protein, maybe the antibodies to spike protein that we make also happen to recognize part of this PF4 molecule and form these complexes. So there’s cross-reactivity. They’re kinda similar, not quite, but similar enough that in some people you get this cross-reactivity. Well, they looked at a ton of coronavirus patients and found that pretty much none of them, really, had PF4 antibodies.

So it wasn’t happening at any significant rate in people who had natural coronavirus infection and they had spike protein. And then if you look at the mRNA vaccines that also cause you to make spike protein, you’re not seeing these clots. So that doesn’t look like it’s it. It doesn’t look like it’s cross-reactivity with spike protein, ’cause that would be a problem. That would be a problem for all our vaccines and it would be a problem for natural infection as well. You would expect then that you would get PF4 antibodies and this disseminated intravascular coagulation, heparin-induced thrombocytopenia-like syndrome, which, by the way, they’re calling vaccine-induced immune thrombotic thrombocytopenia, or VITT, V-I-T-T. I’m just gonna explain each of those words.

Vaccine-induced, we understand. Immune, meaning having to do with our immune response. Thrombotic, thrombus is a clot. Thrombotic means clotting. And then thrombocytopenia means low platelets. So that’s to distinguish it from heparin-induced thrombocytopenia, all right? So it doesn’t look like it’s this cross-reactivity because then all our vaccines would cause it and natural infection would cause it, the PF4 mediated path, which we don’t see. So thankfully, it’s not that. Well, what else could it be? What is unique about this vaccine relative to, say, the mRNA vaccines? Well, it uses DNA and it uses a chimpanzee adenovirus vector that delivers that DNA to teach ourselves how to make spike protein.

The chimp adenovirus doesn’t replicate in humans, so you have to give a large amount in order to get enough cells notified of this DNA so that they make spike proteins so you get enough of immune response. About 50 billion viral particles have to be administered in the dose in order to get this response. Now, the investigators theorized, well, what if some of those viral particles degenerate before they enter the cells, release raw DNA? And DNA is negatively charged and can bind to the positively charged PF4, forming a complex that then induces antibodies because, it might not normally, right?

We know that raw DNA floating around outside of cells can cause an immune response but it doesn’t normally cause a severe immune response unless you’re also getting a vaccine that’s introducing a ton of virus that is jazzed up your immune response. So, again, you’re a little more likely to form these antibodies in the setting of raw DNA floating around. Well, that’s a theory. How often does it happen? Well, exceedingly rarely in what we’re measuring, which we’ll talk about, but that could be one theory. Well, that’s worrisome for the Johnson & Johnson vaccine which uses an adenovirus vector. It’s not chimpanzee.

It’s human adenovirus 6, I believe, that does not replicate in humans right now the way they’ve administered it, but it still uses DNA. So could it be that that’s also gonna be a problem? Well, turns out both FDA and the European Medicines Agency are currently investigating reports, early reports, about six million people vaccinated for the Johnson & Johnson so far, I believe, in the US and they’re starting to investigate, could there be some similar unusual clotting with low platelets? They better look carefully because, again, there’s plausibility there.

And we’re gonna talk about what that means for you and the Johnson & Johnson and AstraZeneca vaccine in a second. So that’s one theory. The other theory is that people have naturally occurring, a small number of people have natural occurring antibodies to PF4 but they develop a tolerance called peripheral tolerance where they don’t generate all this autoimmunity. But in the setting of the vaccine, the immune response is jazzed up and for some reason, or a combination of reasons, that peripheral tolerance is short circuited and they develop this, again, autoimmune response to PF4 and clotting cascade. By the way, it’s treatable with intravenous immunoglobulin and anticoagulation and support, but again, you don’t wanna have this because it can be fatal, right?

It’s an unusual and severe disease and you take it very seriously, which the investigators are. So that being said, those are the kind of theories as to why this might be happening. We think now, and it took a minute to make sure that this is causation. I did a previous video on this where I said, “Hey, it’s possible but we don’t know yet.” Now I’m saying it’s most likely true that there’s causation. It’s not a switch where you go, this causes this. You have to build a case, right? And I think the case is pretty compelling.

So now we gotta look also at J&J and now we gotta look at, what the heck do we do? How do we think about risk? And what does it mean? This is where it gets interesting. All right, so I’ll tell you what the Europeans have done. The Europeans, for example, the Germans and the French, have said: Okay, let’s not give this vaccine, AstraZeneca, to young people because it seems that young people have a lower risk of severe COVID to begin with, so the risk of the disease you’re trying to prevent is lower, and they have a higher risk of getting this unusual syndrome.

Let’s talk about what that risk is. If you look at, 34 million people got the vaccine, 222 had this disease, that’s .0006% of people will get this syndrome. That is a very small rate. It’s about one in, I think in that case, about one in 250,000. But they looked in England and they said, “Okay, we’ve done some math here.” A population in their 20s, between 20 and 29, has about a 1.1 in 100,000 risk of having this unusual clotting disorder as a result of the vaccine. So then you have to look at, well, what’s the risk of COVID in that population? It varies between .9 in 100,000 and 6.9 in 100,000, depending on how much exposure you get, what your job is, where you live, so on. So remembering that, and I’m talking about risk of being ICU hospitalized with COVID. So you’re gonna get blood clots from COVID, right?

It’s higher than the risk of the vaccine in most cases. So what the Europeans did was they said, “Okay, well, let’s figure out what we can do.” It turns out this isn’t the only vaccine available. There are the mRNA vaccines. So in that setting, let’s allow people, you know, 50 or 60 and over, depending on whether you’re in Germany or France, to get AstraZeneca because, again, risk of blood clots lower, risk of COVID higher, and people younger than that shouldn’t get it. So they made that risk assessment and you can understand now why they would say that, right?

Now, imagine you’re in Australia where the prevalence of coronavirus is very low. Well, a young person then, in order to get benefit from the AstraZeneca vaccine, would have to have a higher risk of COVID, and they don’t. So now you’re just exposing to a one in 100,000 risk of a severe illness with not much of a benefit. Maybe they had a .1 in 100,000 risk of COVID. Now you see the calculation’s different.

Maybe the Australians don’t wanna use AstraZeneca in young people either. So that’s how you kind of have to think about it, understanding that, again, you have to look at the risk of the real disease, right? Which, if you assume a infection fatality rate of .3, say, is still quite a bit higher than the risk of this vaccine. Now, if there were no other vaccine in the world, this is me editorializing, if there were no other vaccine in the world, and for many people, ’cause AstraZeneca is the great hope for the developing world.

It’s cheap. It’s refrigerator stable. That is the truth. So for that sort of scenario, the risks of the vaccine are far outweighed by the benefits of the vaccine and it still makes sense to get it, but it makes sense, also, to science the crap out of what’s going on so that we can early recognize any signs and symptoms, maybe avoid it in highest risk populations, especially people taking blood clot and, you know, increasing medications, like oral contraceptives, et cetera, although, we don’t know yet what exactly that does in this syndrome, and modulate from that.

Now, what about, like, say, the US where you have two mRNA vaccines that don’t appear to do this at all and you have the Johnson & Johnson vaccine which we don’t know yet which we need to explore very carefully, in young people especially, well, what would you say? Well, I think you try to promote the vaccines that have the lowest risk if cost is not an issue and access is not an issue, right? So that’s how you’d have to think about it. And I think the party line is people are saying, “Get whatever vaccine you can get,” but that’s how I think about it. I think that’s how a lot of people who parse risk think about it. A public health official might say, “Well, get the vaccine that’s available,” because they’re looking at a whole population, right? And you’re looking at you. Should you get a vaccine at all? Oh, hell yes.

I mean, unless you just had COVID or, you know, you’re a kid, which I’m still, I wanna see data on, you know, kids younger than 12, like, they’re low risk for COVID as it is, you should get a vaccine. If you look at Israel’s data now half their population’s been vaccinated, their rates in hospitalizations have plummeted. So this is our way out of the pandemic. The fact that we’re catching these very unusual cases, I mean, again, .0006%, we’re catching it, means that science and the scientific method and the surveillance apparatus is working in this case and we need to continue it and we need to actually understand that that should give us some faith in the process and we need to keep reevaluating and updating our prior assumptions as we get more data. So that’s kind of my take on this.

We’re gonna do more talks about how variant hysteria is actually not justified with these vaccines yet and you’re gonna see, there’s gonna be, you know, misinterpretations of data coming out of Israel. I can’t wait to talk about this. So there’s much more coming.

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