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Home » Myocarditis and COVID vaccines – what are the facts?

Myocarditis and COVID vaccines – what are the facts?

The link between myocarditis and COVID-19 vaccines has returned (or continued) to the forefront of the anti-vaccine world. Although several studies and a warning from the CDC have indicated that there is a potential link between myocarditis and COVID-19 vaccines, it does not mean it happens frequently or that it means that the vaccines are worse than the diseases.

Though I might be exaggerating, it appears that too many people round up the risk of myocarditis after getting the vaccines to 100% while reducing the risk of myocarditis (and death) from COVID-19 down to 0%. That’s not how statistics work.

This article will review what is myocarditis, what is the risk of contracting it with vaccines, and the actual benefit of the COVID-19 vaccines compared to catching the disease.

medical stethoscope with red paper heart on white surface
Photo by Karolina Grabowska on

What is myocarditis?

Myocarditis, also known as inflammatory cardiomyopathy, is a very rare inflammation of the heart muscle. Symptoms may include shortness of breath, chest pain, decreased ability to exercise, and an irregular heartbeat. The duration of the condition can vary from hours to months. Complications of myocarditis may include heart failure due to dilated cardiomyopathy or cardiac arrest.

Most of the time, myocarditis is caused by an infection that reaches the heart. When it does, the immune cells that fight the infection enter the heart. These immune cells produce biochemicals that can damage the heart muscle. Consequently, the heart itself can become thick, swollen, and weak.

Many of the cases are caused by a virus that reaches the heart. These include influenza virus (flu), coxsackieviruscytomegalovirus, and adenovirus. The condition may also be caused by bacterial infections such as Lyme disease, streptococcus, mycoplasma, and chlamydia.

As you can see, infectious pathogens, such as viruses and bacteria, are almost always implicated in the etiology of myocarditis. And remember, all of the COVID-19 vaccines do not contain live SARS-CoV-2 virus, they only have a piece of code for the spike protein of the virus.

In the vast majority of cases, the effects are temporary, and the condition resolves itself within a few weeks or days. In general, it does not kill or permanently harm those who develop myocarditis.

Photo by Artem Podrez on

Myocarditis and COVID-19 vaccines

There is solid evidence that COVID mRNA vaccines that were developed by Pfizer-BioNTech and Moderna slightly increase the risk of developing myocarditis, especially in young men who have received two or more doses of the vaccines.

However, and I cannot stress this enough, the risk is extremely small. According to a published study, there were 224 verified cases of myocarditis among vaccinated children and young adults in the USA from late 2020 (when the vaccines first became available) to mid-2022 out of the over seven million vaccine doses that were administered. That is around 3.2 cases per 100,000 vaccinations. For context, the risk of dying in a car accident is around 1 per 100 during a lifetime, or 3000X more risky than the vaccine.

Furthermore, according to a published study, most patients recover from myocarditis after at least 90 days. In almost all cases, the condition quickly resolves itself without long-term harm to the individual.

One last thing — the CDC and other researchers have observed no deaths linked to myocarditis after COVID-19 vaccines.

Myocarditis and death from COVID-19

As I wrote above, boys and men between the ages of 16 and 29 have a higher risk of COVID-19–vaccine-related myocarditis. However, according to a CDC investigation, heart inflammation is seven or eight times more common after SARS-CoV-2 infection. And the data suggest that young adults with myocarditis possibly linked with COVID-19 vaccines recover quickly with supportive care.

Simply put, the risk of myocarditis from COVID-19 is substantially higher than the risk from vaccines.

I know some will claim that they don’t need the vaccine because they won’t get COVID-19 because of reasons, so they don’t have to worry about the risk of myocarditis from either. Well, that’s just magical thinking. Individuals who get the vaccine generally do not contract COVID-19 or they have a milder case of the infection without any complications, such as myocarditis or death.

No one is trying to dismiss the risk of myocarditis after receiving the COVID-19 mRNA vaccines. It’s just that the risk is miniscule, even after hundreds of millions of doses across the world. And the risk of myocarditis is much greater from a COVID-19 infection. Furthermore, myocarditis is generally not deadly nor permanent.

We need to weigh risks, something that humans find difficult. If someone hears about a myocarditis case, they turn that into a 100% risk. But that’s not science-based, that’s selection bias at its worse.


Michael Simpson

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