Hello, welcome to my channel Medicine with Dr. Moran. I'm Dr. Keith Moran. Today I want
to talk about additional research in regards to vaccine-induced thrombosis which has been well
documented with the adenoviral vector vaccines in other words the AstraZeneca and J & J. It's highly
likely to be present in the other adenoviral vector vaccine such as the Russian vaccine
Sputnik. I have previously talked about the possible pathophysiology of how these adenovirus
vector vaccines lead to blood clots and ultimately low platelets. Now low platelets occur through a
mechanism where the platelets get consumed in the clot so when we measure the platelet values
they're quite low. Now this condition similar to what we call heparin-induced blood clots
and low platelets. Heparin is a blood thinner that we use to prevent and treat blood clots.
Now this week some new additional information on the pathophysiology of vaccine-induced blood clots
was reported in the journal of Science Advances. There's a link to the research paper in the
description below. Now understanding how the mechanism that is how these vaccines induce
blood clots which can be fatal is important not just to prevent the outcome but also to treat it.
We also need to understand this because we use adenovirus viral vectors to deliver
treatments. Now just a quick recap on this particular condition the frequency is on the
order of one in thirty thousand to about one in a hundred thousand. A review at the end
of July in the journal Blood reviewed the United Kingdom experience with AstraZeneca
and the U.S. experience with J & J up to sometime in July. As you can see on the slide
there are a number of cases of cerebral vein thrombosis. This is an unusual kind of blood
clot that we can see involving the veins of the brain and these veins drain the brain
and of course if you get blood clots in there it will not drain the brain properly. It's an
unusual diagnosis I must say I've only managed a couple of people with this in my 30-year career.
Blood clots also were being found in other areas which were not usual including the
abdominal blood vessels. The majority of the blood clots were seen after the first dose.
18% of people in the Uk group died and 11% in the U.S. group so pretty significant mortality. Now
previous studies which I've reported on previously highlight the role of platelet factor 4 which we
know is what happens with this heparin-induced blood clotting. It can occur in veins as well as
arteries just like the vaccine-induced condition I'm talking about. Here's the research paper. The
researchers studied three different adenovirus vectors which have been deployed as vaccination
vectors in the different Sars Cov2 vaccines. This model of the AstraZeneca viral vector they had to
determine. They had to elucidate where there might be binding with platelet factor four and how it
actually would bind and whether it was plausible. They ultimately showed that the adenovirus vector
combined with platelet factor four via an electrostatic interaction something like
something electrically positive joining was simply electrically negative. In other words opposites
attracting. They showed that a stable complex gets formed with the vector and platelet factor four.
Now platelet factor four is only present in the bloodstream so this kind of interaction does not
occur in muscle cells where the vaccine might be. They did look at a common medication called
Fondaparinux which is an anticoagulant that I've used many times for both acute coronary
syndromes such as heart attacks as well as blood clots in the leg and the lung and they
found that this medication reduces the number of binding events with the adenovirus vector surface
from AstraZeneca and platelet factor four. So it ablates this electronegative potential between
there and inhibits the binding suggesting that this might be a plausible treatment.
Now their study was performed in test tubes on the bench in the laboratory not in humans
but they did show that platelet factor four does contact the surface of this adenovirus vector
when allowed to freely move around in simulations. Vaccine-induced blood clots typically occur 5 to
24 days after vaccination which is the time frame where you're going to get an antibody response.
Now complete elucidation of what truly happens has not completely been worked out but this
schematic provides the best evidence that we have as to what's happening so far. Now first someone
will get vaccinated and somehow the vector enters the bloodstream either by an injection that does
not truly go into the muscle in other words it goes into a small blood vessel directly
due to injection technique or more specifically lack of aspiration and the needle is actually in
the blood vessel when the injection occurs. If there's damage to tiny capillary blood vessels
as the needle is inserted where small amounts of the vaccine might be able to gain access to
the bloodstream even though the vaccine might be placed correctly into the deltoid muscle
this could be the case as well. Perhaps there's another mechanism which I haven't thought of where
some vaccine particles can actually access the bloodstream. Then in schematic two as you can see
there is that electrostatic positive and negative attraction of platelet factor 4 to the vector
and the complex then gets engulfed by other cells because they see it as being foreign.
They send it to one of your lymph nodes which then stimulates the b cells in the lymph nodes
to generate anti platelet factor four antibodies or antibodies against the whole complex. Now these
antibodies then activate platelets and a number of factors are released which causes more platelets
to clump together in more platelet factor four ultimately it causes clot formation and thus the
syndrome of vaccine-induced blood clots and low platelets. Again the platelets are low because
all of the platelets are bound within the clot and they're not freely circulating in the bloodstream.
Now this is important research for many reasons as I mentioned earlier. This key feature
is that this happens in the bloodstream and while we can't definitively say that this happens due to
vaccination technique it could certainly be. It's obviously important when injecting the needle into
the deltoid muscle that you deliver the vaccine into the muscle and not into a tiny blood vessel.
As I mentioned previously on this particular video this does happen based on surveys of nurses
that have given intramuscular injections over the years. Many of them have said
that they have aspirated blood just before they're about to inject the intramuscular injection and so
they always check before they inject. Now it would be terrible to find out down the road that this is
something to do with side effects that's the lack of aspiration when it could have been preventable.
Of course we don't know that that's definitely the cause there's lots of vaccinations going on and a
randomized trial would be interesting and could definitively answer the question. It wouldn't be
that difficult to do. You would obviously need a lot of patience given the low frequency of
the side effects involved but of course we are vaccinating a lot of people right now.
I have told my patients who have encouraged vaccination to make sure that they ask the
person doing the vaccination to aspirate before injection. It's such a small accommodation of only
about three seconds. It makes me think about all the requests that my patients often ask me for,
reasonable requests. I think of things like medications that they may or may not want before
a procedure or at other times sometimes they have requests of getting them positioned in a certain
spot for their endoscopy just before I'm about to sedate them they might want an extra pillow
or a pillow between their knees to make sure that their back is comfortable while they're asleep for
20 minutes. If their accommodations are reasonable and not harmful, I always follow their wishes.
Often it doesn't take any additional time but it shows that I care. It shows people
that I'm listening to them and it allows for shared decision making which is crucial in
the doctor-patient relationship. It ultimately means that they will be happy and so will I.
Asking for someone to aspirate before injecting as I did before both of my vaccinations is not
much to ask for even if it's not the usual way that the vaccinator might perform their task.
Healthcare providers should always be receptive to those that they're delivering care to
being inflexible or emphatic in their beliefs and deciding that it's their way or the highway
so to speak that has no place in medicine. Thanks for joining me today on Medicine with Dr. Moran.
I'm Dr. Keith Moran. Get healthy and stay healthy.