Acute Myocarditis Following COVID-19 mRNA Vaccination in Adults Aged 18 Years or Older

SWAlexander

SWAlexander

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In this population-based cohort study of 2 392 924 individuals who received at least 1 dose of COVID-19 mRNA vaccines, acute myocarditis was rare, at an incidence of 5.8 cases per 1 million individuals after the second dose (1 case per 172 414 fully vaccinated individuals). The signal of increased myocarditis in young men warrants further investigation.
Article: https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2784800
 
Pyrrhus

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We know that SARS-CoV-2 infects the heart muscle tissue.

We also know that most SARS-CoV-2 infections produce no symptoms.

So, if someone receives the SARS-CoV-2 vaccine and suddenly experiences inflammation of the heart muscle tissue (myocarditis), the obvious explanation is that the person had a silent infection of the heart muscle tissue and the vaccine gave the immune system a boost to start attacking the silent virus in the heart muscle tissue.

So why blame the vaccine when it's much more logical to blame the virus?
 
SWAlexander

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Pyrrhus said:
We know that SARS-CoV-2 infects the heart muscle tissue.

We also know that most SARS-CoV-2 infections produce no symptoms.

So, if someone receives the SARS-CoV-2 vaccine and suddenly experiences inflammation of the heart muscle tissue (myocarditis), the obvious explanation is that the person had a silent infection of the heart muscle tissue and the vaccine gave the immune system a boost to start attacking the silent virus in the heart muscle tissue.

So why blame the vaccine when it's much more logical to blame the virus?
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Exactly. But how does the patient know if there was never a diagnosis?
Then there are doctors like Khullar: "On Taking Long COVID Seriously" https://www.socialsciencespace.com/2021/10/on-taking-long-covid-seriously/
 
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Pyrrhus

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Cipher said:
Another hypothesis; Insights from a murine model of COVID-19 mRNA vaccination-induced myopericarditis: Could accidental intravenous vaccine injection induce myopericarditis?
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Thanks for sharing that hypothesis! That (Can et al.) mouse model is indeed interesting and a bit surprising, and it is also plausible that a vaccination could accidentally hit a vein instead of muscle tissue, but the type of myocarditis demonstrated in the mouse model might be different from the type of myocarditis seen in practice:

From your link:
Can, L et al. (reference) have described an important and novel murine model of COVID-19 mRNA vaccination with features of myocarditis and pericarditis, i.e., myopericarditis. This murine model has the potential to provide significant insights into the pathogenesis of myopericarditis after COVID-19 vaccination via intramuscular and intravenous routes.

For example, the authors demonstrate in their paper that the inflammation in the myocardium after intravenous injection of the vaccine consists primarily of CD68+ macrophages or histiocytes, but not CD3+ T-lymphocytes. In comparison, evaluation of tissue from two patients suspected to have post COVID-19 mRNA vaccination related myocarditis demonstrated T-cells and macrophages, admixed with eosinophils, B cells, and plasma cells However, the myocarditis in those cases were only temporally associated with the vaccine (5).
[...]
It is important to note that future applications of the murine model system will likely require further investigation into how well this model represents the rare complication of myopericarditis following COVID-19 mRNA vaccination in humans.

For example, it is often challenging to correlate the dose of a drug when adjusted to body weight between a small mouse and a much larger human. In this case, the mouse received 0.25 mcg per gram weight. The Pfizer mRNA vaccine dose in humans is 0.4 x 10-3 mcg per gram for a 70 kg person.

Additional investigation will also be needed to determine the effect of murine strain in the model system of myopericarditis. This is particularly true since Balb/c mice, used in the study by Can, L et al., have a propensity to develop cardiac calcinosis (6).
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hapl808

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Pyrrhus said:
So, if someone receives the SARS-CoV-2 vaccine and suddenly experiences inflammation of the heart muscle tissue (myocarditis), the obvious explanation is that the person had a silent infection of the heart muscle tissue and the vaccine gave the immune system a boost to start attacking the silent virus in the heart muscle tissue.
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That's an interesting theory. And so it's possible that any viral infection could get reactivated and cause a problem, but also possible that the boost in the immune system could suppress a chronic infection? That might explain why some people improve and some get worse. Would be nice to have a more developed pre- and post- vaccine protocol for people with autoimmune dysfunction or possible latent viral issues.
 
Pyrrhus

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SWAlexander said:
I had thrombosis after the first vaccination.
Thrombotic Thrombocytopenia after ChAdOx1 nCov-19 Vaccination: https://www.nejm.org/doi/full/10.1056/NEJMoa2104840
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@Cipher's link also mentions a mouse model trying to explain the thrombosis from that adenoviral-vector vaccine:
For example, in a preprint, Nicolai L. et al describe a murine model of an adenoviral vector vaccine for COVID-19 using the ChAdOx1 nCov-19 vaccine that has been linked to a rare thrombosis with thrombocytopenia syndrome. They demonstrate that intravenous injection of this vaccine leads low platelet counts, clot formation and platelet activating PF4-polyanion antibodies similar to thrombotic thrombocytopenia (4).
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To me, it also seems likely that people who experience thrombosis from an adenoviral vector vaccine may have had prior exposure to a similar adenovirus. This has always been a theoretical concern in the development of adenoviral-vector-based vaccines.
 
Pyrrhus

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hapl808 said:
And so it's possible that any viral infection could get reactivated and cause a problem, but also possible that the boost in the immune system could suppress a chronic infection? That might explain why some people improve and some get worse.
Click to expand...

That's also a very interesting idea indeed, albeit a far broader statement than the one I made.

hapl808 said:
Would be nice to have a more developed pre- and post- vaccine protocol for people with autoimmune dysfunction or possible latent viral issues.
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Yeah, would be nice. But at this point, I would simply settle for a more solid understanding of the origins of autoimmunity itself and a more solid understanding of viral persistence in the general population...
 
SWAlexander

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Pyrrhus said:
That's also a very interesting idea indeed, albeit a far broader statement than the one I made.



Yeah, would be nice. But at this point, I would simply settle for a more solid understanding of the origins of autoimmunity itself and a more solid understanding of viral persistence in the general population...
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I wonder if any Long COVID or ME/CFS patients had a Thymus exam?
 
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